The biodegradation of the organochlorine insecticide, γ‐BHC (γ‐isomer of 1,2,3,4,5,6‐hexachlorocyclohexane) was evaluated for four Philippine rice soils: Casiguran sandy loam, Luisiana clay, Maahas clay and Pila clay loam. Rapid degradation of the insecticide was observed under flooded soil conditions. The rate of degradation for γ‐BHC was highest in Casiguran sandy loam; none of the parent insecticide remained in the soil after 1 month of incubation at 30C. Organic matter levels were related directly to rate of decomposition. Molecular oxygen, nitrate, and manganic oxide retarded the rate of γ‐BHC degradation. Increased temperature increased the rate of γ‐BHC degradation, and it appears that γ‐BHC residues are unlikely to be a problem in the tropical rice‐growing areas.