The objective of this study was to examine the effect of storage duration of diluted boar semen on sows’ fecundation. The authors used in this experience the bio-preparation “Atropozit” and “M22” as components of the sperm dilution environment. Diluted semen was stored for a period of 2-3 days, 3-4 days, 4-5 days and 56 days at a temperature of 16-18 0C. The fertility rate of sows inseminated with diluted semen that was stored for 2-3 days was different if compared with the semen stored for 4-5 and 5-6 days depending on the used dilution environment. The sows inseminated with diluted semen with the dilution environment in the composition of which the bio-preparation “Atropozit” was introduced and which was kept at a temperature of 16-18 0C for 5-6 days, had a fecundity rate of 70%, and when the preparation “M22” was introduced in the composition of the dilution environment, the fertility rate was 68.7%. The obtained results show that sows’ fecundity is influenced by the dilution environments composition and by the storage duration of semen at temperatures of 16-18 0C.