The industrial area of Upper Silesia is the most polluted region in Poland. To assess if these conditions could influence male fertility, a retrospective analysis of the fertilization potential of donor semen was performed, taking as an outcome measure the pregnancy rate after donor inseminations in 1982–2004. Data on contamination of air and soil in the region were collected and compared with those of the rest of the country. In total 2,100 inseminations using fresh semen from 44 healthy donors with proven fertility in 1,617 cycles in 290 infertile couples were performed in 1982–1995 and 2,010 inseminations using frozen semen from 20 healthy donors with proven fertility in 1,994 cycles in 414 infertile couples were performed in 1996–2004. Significantly higher values of air and soil pollution compared to the rest of the country were stated. Pregnancies occurred in 125 patients inseminated by fresh semen and in 85 patients inseminated by frozen banked semen. The insemination efficiency was lower than expected and a distinct declining trend was observed in both groups. Significant rise in the number of cycles necessary for achieving pregnancy was noted. The fertilization potential of fresh and frozen donor semen in Upper Silesia is low and seems still to be diminishing. It might be speculated that this phenomenon could be caused by the high degree of industrial pollution