A study was conducted from 2001 to 2003 in the Gulf of Gdańsk (Poland) on the diel food composition and diel and seasonal changes in the feeding activity of Pomatoschistus minutus, Pomatoschistus microps, and Platichthys flesus. During the three-year study, no empty fish stomachs were noted, and the fish food was comprised exclusively of prey species that inhabit the shallow water zone (e.g., Bathyporeia pilosa). It can also be stated that the shallow waters of the Gulf of Gdańsk are an important feeding ground for Pomatoschistus sp. and P. flesus. The food intake of all three investigated fish was lower at night than during the day, which led to the conclusion that these fish are day feeders. The seasonal feeding intensity of the sand and common gobies was approximately the same throughout the investigation but was higher in April, June, and August, and lower in September. The flounder fed most intensively in August and March, while feeding intensity was lower in May and June. In September 2001, the most important prey items for P. minutus were Amphipoda undet. and Mysidacea undet. in the morning, N. integer and Mysidacea undet. at noon, and Harpacticoida and Copepoda undet. in the evening. In the same month, P. microps fed mainly on B. pilosa at 08:00, N. integer at 00:00, and Harpacticoida at 20:00. From 2001 to 2003, P. flesus preyed mainly on Polychaeta in the morning hours, while in the evening it targeted N. integer according to the prey frequency of occurrence and quantity in the fish stomachs.