Under bleaching conditions, corals lose theirsymbiotic zooxanthellae, and thus, the ability to syn-thesize fatty acids (FAs) from photosynthetically derivedcarbon. This study investigated the lipid content and FAcomposition in healthy and bleached corals from theOdo reef flat in Okinawa, southern Japan, following ableaching event. It was hypothesized that the FA com-position and abundance would change as algae are lostor die, and possibly microbial abundance would increasein corals as a consequence of bleaching. The lipid con-tent and FA composition of three healthy coral species(Pavona frondifera, Acropora pulchra, and Gonia streaaspera) and of partially bleached and completelybleached colonies of P. frondifera were examined. TheFA composition did not differ among healthy corals, butdiffered significantly among healthy, partially bleached,and completely bleached specimens of P. fro ndifera.Completely bleached corals contained significantly lowerlipid and total FA content, as well as lower relativeamounts of polyunsaturated FAs and higher relativeamounts of saturated FAs, than healthy and partiallybleached corals. Furthermore, there was a significantlyhigher relative concentration of monounsaturated FAsand odd-numbered branched FAs in completelybleached corals, indicating an increase in bacterial col-onization in the bleached corals.