Twenty-five infertile males with 5 or more pus cells per 1000 x field in their seminal fluid were randomly assigned to treatment with minocycline 200 mg daily for one (Group A) or two (Group B) weeks. At the end of the treatment period a statistically significant reduction of pus cells, and a statistically significant increase in the sperm count and the motile sperm were observed (Wilcoxon matched-pairs signed-ranks test, p < 0.01). No statistically significant differences were observed between the two groups (Mann Whitney U test). No toxicity was reported. In conclusion, minocycline improves the seminal indices, in infertile males with high pus cell count in their seminal fluid.