Three new macrocyclic lactones, lituarines A, B, and C, were isolated from the New Caledonian sea pen, Lituaria australasiae. Structure elucidation of these compounds was determined through NMR spectroscopic techniques. Lituarines are the first macrocyclic lactones of marine origin exhibiting two coupled tetrahydropyran moieties. Antifungal, cytotoxic and antineoplastic activities were found for these substances.