Three new C- seco limonoids (1—3) and one new tetracyclic limonoid (4) were isolated from a methanol extract of the ripe fruits of Melia azedarach collected in Curitiba, Brazil, and their structures were elucidated by spectroscopic data analysis and comparison of spectral data with those of the previously known compounds. Among the limonoids isolated in the present study, compounds 3 and 4 exhibited significant inhibitory activity against HeLa S3 cancer cells, whereas 1 and 2 showed weak cytotoxicity.