Attempts were made to recover valuable organic matter from wastewaters from the fishmeal industry. The most efficiency system was flocculation with ferric chloride. The optimal conditions for flocculation with this salt were developed and successfully assayed on an industrial scale. The treated effluent had a large organic load and so ultrafiltration was also carried out. The results suggest that ultrafiltration removed a high percentage of the remaining proteins, but that it would require a large membrane area and troublesome washing procedures to maintain an adequate flux rate. Ultrafiltration was therefore considered inappropriate for secondary treatment on an industrial scale.