Unripe avocado fruit (Persea americana) was subjected to a bioactivity-directed fractionation, as monitored via the brine shrimp lethality assay, to isolate three major bioactive constituents (1-3). Compounds 1-3 all have a 1,2,4-triol moiety and a long aliphatic chain that terminates as either an alkane, alkene, or alkyne, respectively; 1 is new, while 2 and 3 have been described previously but not as cytotoxic or pesticidal agents. All have activity against six human tumor cell lines in culture and show selectivity for human prostate adenocarcinoma (PC-3) cells with 3 being nearly as potent as adriamycin. Also, when tested against yellow fever mosquito larva, 3 was more effective than rotenone, a natural botanical insecticide and positive control.