The aim of the present study was to analyze the frequency of occurrence of acrosome-reacted spermatozoa in semen stained with two methods, depending on boar semen storage time. The studies were conducted on ejaculates collected from 10 Landrace boars used in artificial insemination. The smears were prepared by means of two staining methods: SpermBlue and eosin-gentian dye. It was concluded that the proportion of acrosome-reacted spermatozoa depends on the staining method and ejaculate storage duration. When the smears were stained with the SpermBlue method, the number of spermatozoa with head defects, including acrosome reaction, was greater compared with the smears stained with the eosin-gentian dye. With the passage of semen storage time, a change in sperm count with an acrosome reaction was observed. In the SpermBlue-stained smears, the proportion of acrosome-reacted spermatozoa was the highest in the 96th hour of storage and was about 2.5%. An increase in the number of acrosome-reacted spermatozoa was observed in the semen stained with the eosin-gentian dye method in the following semen storage hours.