Bromoiodomethane is a halomethane with the formula BrCH<sub>2</sub>I. It is a colorless liquid, although older samples appear yellow. The compound has been investigated as a reagent for cyclopropanation by the Simmons-Smith reaction, but diiodomethane and chloroiodomethane are preferred. It also occurs naturally as the result of microbial action.
Its critical point is at 367.85 ðC and 6.3 MPa and refractive index is 1.6382 (20 ðC, D).