Background: The presence of leukocytes, detected by peroxidase test in semen, can be a good indicator of infections in the male genital tract. Peroxidase positive cells have been positively correlated with elevated values of elastase, one of the major proteases liberated by granulocytes at the inflammation place. However, seminal granulocytes may not be adequately detected by the peroxidase test in comparison with immunological methods. Aim: To correlate the determination of peroxidase positive cells with the elastase level in the seminal plasma. Material and methods: Seminal plasma from 64 patients with a high number of round cells (>106/ml) in semen, was studied. Correlation analysis was done using the Pearson correlation coefficient. Results: No correlation between the level of granulocyte elastase and the number of peroxidase positive cells (r=0.2237, p >0.05), or even the number of round cells (r=0.03934, p >0.05) was observed. Conclusions: Our results suggest that the determination of peroxidase positive cells is not a reliable indicator of leukocytes in the seminal plasma and their absence do not discard a silent genital tract infection (Rev Méd Chile 2003; 131: 613-616)