Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece
and leave with the element ID LEGO asks for, or a link to buy the part.
Brick Special 1 x 1 with Stud on 1 SideBluePart 87087Element 4583862×4
Brick Wedged, Curved 2 x 1 with Stud Notch LeftBluePart 29120Element 6172414×3
Brick Wedged, Curved 2 x 1 with Stud Notch RightBluePart 29119Element 6172411×3
Cone 1 x 1 [Top Groove]BluePart 59900Element 4529235×26
Plate 1 x 2BluePart 3023Element 302323×20
Plate 1 x 4BluePart 3710Element 371023×20
Plate 2 x 2 CornerBluePart 2420Element 242073 or 242023×18
Plate 2 x 8BluePart 3034Element 303423×3
Plate 4 x 6BluePart 3032Element 303223×5
Plate 6 x 8BluePart 3036Element 303673 or 303623×8
Plate Round Corner 4 x 4BluePart 30565Element 6146306 or 4143267×2
Plate Special 1 x 2 Rounded with 2 Open StudsBluePart 35480Element 6315482×4
Technic Pin Long with Friction Ridges Lengthwise, 1 Center SlotBluePart 42924Element 6299413×4
Tile 1 x 1 with GrooveBluePart 3070bElement 4206330 or 307073×2
Tile 2 x 3BluePart 26603Element 6196596×10
Tile Round 1 x 1 QuarterBluePart 25269Element 6302961×2
Wedge Plate 2 x 2 LeftBluePart 24299Element 6189198×13
Wedge Plate 2 x 2 RightBluePart 24307Element 6189202×13
Wedge Plate 3 x 2 LeftBluePart 43723Element 4498156 or 4280150×6
Wedge Plate 3 x 2 RightBluePart 43722Element 4498155 or 4280149×6
Wedge Plate 3 x 6 Cut CornersBluePart 2419Element 241923×1
Lime
144 pieces
Tile Round 1 x 1LimePart 98138Element 6284583 or 6057878×100
Tile Round 2 x 2 with Bottom Stud HolderLimePart 14769Element 6092766×42
Wedge Plate 8 x 8 Cut CornerLimePart 30504Element 6424330×2
Green
75 pieces
Brick Curved 4 x 2 No StudsGreenPart 93606Element 6285601 or 6100244×4
Plate Special Round 1 x 2 Half Circle with Stud (Jumper)GreenPart 1745Element 6510059 or 6424859×19
Tile 2 x 2 Curved, MacaroniGreenPart 27925Element 6365611×4
Tile Round 1 x 1 QuarterGreenPart 25269Element 6150607×6
Tile Special Round 2 x 2 with HoleGreenPart 15535Element 6074954×42
Yellow
51 pieces
Brick 1 x 4YellowPart 3010Element 301024×1
Plate 1 x 2YellowPart 3023Element 302324×15
Plate 1 x 4YellowPart 3710Element 371024×8
Plate Round 4 x 4 with Pin HoleYellowPart 60474Element 4515349×8
Plate Special 1 x 1 with Clip Vertical [Thick Open O Clip]YellowPart 60897Element 6348065 or 4613258×5
Plate Special 6 x 12, Studs on 3 Edges with 'The Amazing Spider-Man' PrintYellowPart 6178pr0007Element 6434916×1
Technic Beam 3 x 3 T-Shape ThickYellowPart 60484Element 6072627×2
Technic Brick 1 x 2 [1 Pin Hole]YellowPart 3700Element 370024×6
Technic Pin Connector Plate 1 x 2 x 1 2/3 [Two Holes On Top]YellowPart 32530Element 6247387 or 3253024×2
Tile 1 x 3YellowPart 63864Element 4558172×1
Turntable 4 x 4 Square Base, LockingYellowPart 61485Element 6310219×2
Yellowish Green
49 pieces
Tile Round 1 x 1Yellowish GreenPart 98138Element 6284598×27
Tile Round 2 x 2 with Bottom Stud HolderYellowish GreenPart 14769Element 6424480 or 6113047×22
Light Bluish Gray
7 pieces
Brick Curved 2 x 2 x 2/3 Two Studs and Curved Slope EndLight Bluish GrayPart 47457Element 4494475×2
Brick Wedged 3 x 3 FacetLight Bluish GrayPart 2462Element 4211718×1
Brick Wedged, Curved 1 x 2 x 2/3 No Studs, Wing EndLight Bluish GrayPart 47458Element 6375710 or 6254402×1
Plate 2 x 14Light Bluish GrayPart 91988Element 4662161×1
Plate Round 6 x 6 with HoleLight Bluish GrayPart 11213Element 6015349×1
Technic Brick Special 1 x 2 with Pin Hole and 1 x 2 PlateLight Bluish GrayPart 73109Element 6326478×1
Reddish Brown
2 pieces
Technic Axle 5 with StopReddish BrownPart 15462Element 6159763×2
Orange
1 piece
Brick and Axle Separator v2.0OrangePart 96874Element 6240515 or 4654448×1
Tick each piece as you find it, or mark it missing.
When a piece really is missing
Ask LEGO
LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for
the set number and each piece's element ID, the number printed beside the piece in the parts list at the back
of the instructions. This checker lists both.
Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from
older or second-hand sets.
Keep a record
Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick
pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.