Abstract. The objective of this study was to examine semen quality parameters for the Přeštice black-pied breed over a test period of 8 years while considering the potential effects of collection month and boar age. Ninety-nine ejaculates were collected using the gloved-hand technique from healthy and fertile mature boars from selected farms. Ejaculate volumes were relatively low because the boars were accustomed to natural mating. Sperm motility, sperm concentration, percentage of morphologically abnormal spermatozoa (MAS), and sperm motility after 24 h of storage in Androhep extender (dilution rate 1:1.5) were assessed. Significant differences were found in sperm concentration and MAS rate in relation to collection months and boar age in the monitored years (P<0.05). A tendency for MAS to increase with monitored years was observed. Significant differences in sperm motility and motility after 24 h of storage were only observed in relation to collection months (P<0.05). Results of this study detected effects due to collection month and boar age on boar semen quality during the monitored years.