A study was conducted to determine the relationship between levels of serum testosterone and corrected seminal fructose levels in men under basal and post-clomiphene stimulation. A prospective controlled study was carried out in 19 selected men attending the andrology laboratory at the Instituto de Investigaciones de la Altura. These subjects were without any evidence of inflammation in the reproduction tract. The men received 100 mg clomiphene citrate daily for 5 days. Serum testosterone, seminal fructose, and corrected fructose levels were measured before and at the end of clomiphene citrate stimulation. Levels of serum T were related more with corrected seminal fructose than with seminal fructose concentrations under basal and stimulated conditions. Seventy-one percent of subjects with low levels of serum T had low levels of corrected seminal fructose, whereas only 28% of the same subjects had low levels of seminal fructose (uncorrected fructose). The results suggest that corrected seminal fructose may be used as a biological marker of androgen activity in the reproductive tract. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.