Significant developments in the culture of tilapias and seaweeds in the Philippines for 1988-1991 are reviewed. The country was the top producer of the Nile tilapia (Oreochromis niloticus) and red seaweed, Eucheuma sp., in the world during the period. Intensification of cage and pond culture of tilapia in freshwater with artificial feeding was prevalent. The National Tilapia Production Program was launched in 1990 and is being implemented in 26 sites of 12 regions in the country. Culture of sex-inversed tilapias (O. niloticus and O. niloticus x O. mossambicus hybrids) in freshwater cages, brackishwater ponds, and sea cages was pilot-tested for the first time. For seaweeds, studies were made on the culture of other economically-important species such as Gracilaria sp. and Porphyra sp. A trial on the integrated searanching of abalones (Haliotis sp.) and giant clams (Tridacna sp.) with Euchema was also conducted.