1. When regular-sized, go to the tunnel leading into the Deepwood Shrine. You will find this one simply sitting in the corner.
2. Get here via Lake Hylia and head all the way southwest to find this one at the water's edge.
3. After getting the Flippers, shrink down at the stump west of the village, and enter the leftmost tunnel to the northwest. Make it through to get this heart.
4. Follow the path to the right of the main building in town to find this one out in the open.
5. In the room south of the mini boss, this one is in plain sight.
6. Use the blue warp to reach this one on a high ledge.
South Hyrule Field
7. Do the mandatory Kinstone fusion with the musician to open up a cave here. This is the reward inside.
8. In the southwest area, dash into a tree to reveal a stump. Shrink down and get into the water (Flippers required too), then swim into a small hole to the north. You'll find this one in there.
Mt. Crenel's Base
9. After riding the tornadoes to the west, follow the path west and north to a dead-end area. Bomb the wall and go inside to find this, among other treasure.
10. At the base, go west and bomb the wall to the right of the area where rocks fall from above. This piece is inside, as are faeries.
11. After fusing with one of the Mountain Minish, a stalk will grow atop the mountain. Climb it to find this one, as well as some good cash.
12. Once you reach the summit by climbing the high wall, go down a ladder to the left. Enter the cave with the Mole Mitts and dig your way to this heart piece.
13. In the room with Grayblade. To get there, climb up the wall from where you get the Grip Ring, and enter that cave. Clone yourself to enter the room, and you'll see this on the side as usual.
Cave of Flames
14. From where you find the overturned mine cart, go right and bomb the south wall. Enter that room to find this heart piece.
North Hyrule Field
15. To the west of the castle garden entrance, bomb the rock and go down into the cave. Go down to the second basement level inside to find it.
16. From the Lon Lon Ranch entrance to this area, simply follow the path east to find it.
17. When you get the Flippers, take the northeast exit of North Hyrule Field to this place. Swim to the north ledge where this piece is just sitting.
18. After doing a Kinstone fusion in Cloud Tops, swim into the cave behind one of the upper waterfalls. You'll find this one right there.
19. After doing another Kinstone fusion, you'll be able to access a cave on the water which you must dig through to enter. Go inside and get your piece there.
Lon Lon Ranch
20. Dash into the tree behind the house with the Pegasus Boots to reveal a stump. Shrink down and walk east and north onto the small path area. Go through it to find a Piece of Heart at the end.
21. From Lake Hylia, go through the cave with the Mole Mitts, and the west exit will lead to this piece of heart.
22. Push open the giant tombstone and go into the room below to find this.
23. After you get the Flippers and do some Kinstone fusions, ride a lilypad from the stump southward. Make your way all the way south and east through the area to a large body of water. Swim into a small cave and get through it to find this at the end.
24. In the northeast area, enter the cave next to the waterfall (will need Flippers at least to reach here). Inside, go to the right side and push the top/bottom blocks left, and the middle one downward. Then, run in and collect this piece.
25. Go to the tree stump directly west of the Fortress of Winds, and shrink down. Go west and drop down, then climb down the vine to the south. For the next set of vines, climb the middle one. Walk into a cave and collect the Piece of Heart at the end.
Fortress of Wind
26. In the room with the 2 Armos, shrink down and drop through the middle hole. On the bottom level, go into the east room and resize yourself to pick this heart up.
27. Fuse a Kinstone with the Forest Minish at Lake Hylia (you need the Ocarina of Wind to reach him). Then, enter the hole in the tree here to find this piece.
28. Climb the giant stalk that appears after a Kinstone fusion, and you'll find this here among other things.
Hyrule Castle Garden
29. Go into the drained fountain in the upper-right area after a Kinstone fusion. You'll find this Piece of Heart inside.
30. Cut down the bushes in the eastern area of the garden to reveal a garden. Go down to meet the swordsman Grimblade, and find this heart as well.
31. After Simon's Simulations opens up (it's the house with the purple blob on top), agree to play it. Win the fight to get this prize.
32. In the southeast area of town, you'll find 2 houses with a plank connecting the two roofs. Become small in the left house, then go up the vine to the side of the north steps, and enter the inn from a small back entrance. In the small room, you'll find this heart piece.
33. Play the cucco-fetching game many times. Eventually you'll be asked to find 3 in 55 seconds (the one where 2 of them are gold and a good distance away). If you beat this round, you'll finally win this piece.
34. After getting Roc's Cape, stand underneath the town bell and jump to hit it. This heart will fall out of it.
35. After getting Roc's Cape, become small at the west side of town, and make your way through the path with the cats to the fountain cave below. Inside there, walk across the bridge and use the cape to jump the gap and collect the piece of heart.
36. Collect all the figurines in the southwest building of town, then talk to the man sitting outside the cafe. Enter the building north of the cafe and you'll find this piece inside.
37. After you fully power up your sword, visit the school. Become small and go in the courtyard, and walk onto the dirt path. Go all the way up to the glowing tiles, and split into 4 Links to push the block aside, giving you access to the heart.
38. With the Flippers, dive into the pool to the left of the house sitting on the north end of the lake.
39. After you obtain the Flippers, swim all the way to the south shore of the lake. You'll find it sitting right there on the ledge.
40. On an island to the north of the Temple of Droplets, you'll find this one. Use Roc's Cape to hop over by it.
41. Go through the cave with the Mole Mitts (need Roc's Cape to reach this cave). Go up and down the ladders inside and you'll find the stalk (you must first fuse with a Forest Minish in Lake Hylia). Climb it to find this heart.
42. In Waveblade's training room, you'll find this one sitting to the side.
43. In the graveyard area, push the northwest tombstone to reveal steps. Go into the cave below and use 2 clones of yourself to push the block to the side, gaining access to this heart piece.
Palace of Winds
44. On the fourth floor the second time around, head into the north room. Cross the bridge and you'll find this at the end.