L-696229 is a specific inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). L-696229 inhibited RT activity in a mutually exclusive manner with respect to either phosphonoformate or azidothymidine triphosphate and was a weak partial inhibitor of the RNase H activity associated with HIV-1 RT. L-696229 inhibited the spread of HIV-1 infection in cell cultures with all cell types and viral isolates tested.