There are 16 words that start with 'lepto'.
| lepton | leptons |
| leptonic | leptophos |
| leptosome | leptotene |
| leptosomes | leptospire |
| leptotenes | leptophoses |
| leptospiral | leptospires |
| leptocephali | leptocephalus |
| leptospiroses | leptospirosis |
Note: These 16 words that start with 'lepto' are found from the USA & Canada version of the tournament Scrabble word list.