Seventy-nine marine organisms (51 tunicates, 20 sponges, and 8 molluscs) were collected and evaluated as potential sources of new chemotherapeutic agents. Extracts from 33 organisms exhibited cytotoxicity and 8 inhibited microbes. Isolation and structure studies have been initiated with several of these organisms, Peronia peronii (L1210, IC50 0.5 mug/ml), Eudistoma olivaceum (L1210, IC50 0.33 mug/ml) and Dolabella auricularia (L1210, IC50 0.01 mug/ml). Several active metabolites were isolated and structure studies are in progress. During the three year period of this grant isolation work will be undertaken on the remaining active species from the collection noted above.