The apparent digestibility coefficients of dry matter, crude protein and energy in white fishmeal, herring meal, anchovy meal, salmon meal, sardine meal, mackerel meal, squid meal, soybean meal, corn gluten meal and wheat flour were determined for olive flounder. Digestibility coefficients were determined using a reference diet and test diets that contained 70% of the reference diet mixture and 30% test ingredients. All diets contained 0.5% chromic oxide as a digestibility indicator. The fish averaging 220 g were held in 500 L tanks at a density of 20 fish per tank. Feces were collected from three replicated groups of fish using a fecal collection column attached to a fish-rearing tank. The apparent dry matter, crude protein and energy digestibility coefficient values observed were in the ranges 29-79%, 59-95% and 45-91%, respectively, for various test ingredients. The apparent dry matter, crude protein and energy digestibility of white fishmeal, herring meal, anchovy meal, salmon meal, sardine meal, mackerel meal and squid meal were significantly higher than those of soybean meal, corn gluten meal and wheat flour.