BACKGROUND: Urogenital infections and inflammation may contribute significantly to ejaculate parameters essential for male infertility. METHODS: For this review, data were acquired by a systematic search of the medical literature of the last 5 years. RESULTS: We address the andrological relevance of male urogenital infections and inflammation on ejaculate parameters. The different classification systems of the WHO and NIH are illustrated. In most cases, a separation of the different areas of the urogenital tract, for example, of the prostate, epididymis and testicles, is not possible. The significance of bacteriospermia with common bacteria is discussed. Furthermore, HIV, ascending chlamydial, mycoplasmal and gonococcal infections are relevant. Especially, the relevance of sexually transmitted microorganisms seems to be underestimated. Leukocytospermia is not well defined in its biological significance. Seminal plasma elastase and the cytokine expression reveal better insights into the inflammatory response of the seminal pathways. Sperm antibodies and reactive oxygen species are not usable as indicators for infection and inflammation. Different aspects for an impairment of ejaculate quality have been demonstrated although a direct ascension of microorganisms to the prostate has not been confirmed. Probably, lesions of the epididymis may sustain an ongoing disturbance of sperm parameters. A potential negative influence of urogenital infections and inflammation on sperm function is under discussion. However, the severity of impairment differs according to the underlying infections and the involved compartments. CONCLUSIONS: Signs of infections and inflammation in the ejaculate of infertile men are common, and the relevance is often doubtful in spite of microbiological, spermatological and immunological facilities.