On a basis of whole year monthly sampling, the abundance of the flounder in inshore shallow waters of the western part of the Gulf of Gdansk was established. Flounders were observed almost all year. Only in winter, when sea ice forming proc-esses occurred, they disappeared from the investigated zone. The highest abundance of the flounder was noticed in Hel vicinity. No flounders were observed in inshore waters of the Puck Lagoon. Young flounders occurred in the highest number in July (average for all investigated area amounted to 2.81 individuals 100/ m^2). In that month, this-year-born flounders settle in the inshore shallow water zone. The highest biomass was noticed in August (average 4.98 g/100 m^2) when older bigger flounders more frequently inhabited inshore zone. Body proportions of young flounders during their growth in inshore shallow waters of the Gulf of Gdansk are stable. All measured distances were increasing linearly with the growth of flounder length.