Abstract In the system i-Pent 3 BuNBr-H 2 O, along with the known compound i-Pent 3 BuNBr-38H 2 O, three new clathrate hydrates were identified: i-Pent 3 BuNBr-32H 2 O, i- Pent 3 BuNBr-26H 2 O, and i-Pent 3 BuNBr-24H 2 O. Crystals of all the hydrates were isolated, and their compositions were determined.