The effects of various seasons of the year on boars semen quality parameters were investigated on intensive swine production farms in the Autonomous Province of Vojvodina, Serbia. The total of 30 Large White AI boars were investigated, within one year. Two ejaculates per boar per month were investigated (total 720 ejaculates per year). The average ejaculate volume in the June-July-August and September-October-November season (213ml and 232ml), sperm concentration (220 and 210x106/ ml) and total sperm number per ejaculate (46,8 and 48,7x109), were significant (P<0,01) lower compared with December-January-February (293ml, 319x106/ml, 93,5x109) and March-April-May season (285ml, 284x106/ml, 80,9x109). The percentage of poor ejaculates significntly incerase in the wormer season (31,8% i 21,4%), compared with colder season (10% i 16,7%). Due to lower values of ejaculate parameters, fewer doses may be made from one ejaculate in the wormer season. These facts should be taken into consideration when planning the intensity of boar reproductive exploitation in the wormer and colder season of the year.