Three new natural products, bengamide Y (1), bengamide Z (3), and bengazole Z (5), were isolated from the aqueous extract of an Australian collection of the sponge Jaspis sp. Their structures were solved by spectroanalytical methods and by comparison of their spectral data with known bengamides and bengazoles that were reported from the same genus. Bengamides Y (1) and Z (3) showed a striking differential cytotoxicity pattern against a panel of 10 human tumor cell lines, with closely related cell lines (e.g., SNB-19 and SNB-75) displaying significant differences in sensitivity.