A methanol extract of the ripe fruits of Melia azedarach collected in Curitiba, Parana, Brazil, afforded seven new ring C-seco limonoids (1-7) together with three known limonoids (8-10). The structures of the new compounds were elucidated by NMR and MS analysis and comparison of spectral data with those of previously known compounds. Compounds 4 and 5 exhibited significant inhibitory activity against HeLa S3 cancer cells, whereas 1, 2, 3, and 8 showed weak cytotoxicity.