xThe main fishing fleet that lands in Itajaí harbor, Brazil, is the purse-seine one, which represents 30% of the landed weight. This fleet has as target species the Brazilian sardine (Sardinella brasiliensis). The objective of this work is to describe and to analyze the temporal variations of the fishing operation of the purse-seiners between 1997 and 1999. The analyzed aspects were: (1) description of the fleet using the ships length, motor power, crew size, skull and conservation type, hold capacity, and net’s length and height; and (2) temporal variation of the fishing operation using number of tows per trip, time and duration of tows, number of days at sea per trip, number of fishing days per trip and searching time of schools. In the analyzed period, a total of 797 records were obtained. In general, the fleet description indicated that there was an increase of the fishing power in the last 10 years, in spite of the reduction of the number of ships. On the other hand, the results suggest that the characteristics of the fishing operation are related with the oscillations of the target species availability.