A high proportion of prostate cancer and benign prostatic hyperplasia (BPH) have been shown to be dependent on androgen biosynthesis. The biosynthesis of androgens is undertaken by a number of important enzymes such as 17α-hydroxylase/17,20-lyase and 17β-hydroxysteroid dehydrogenase. Through the inhibition of these enzymes it is possible to reduce the amount of androgens present, which in turn reduces the stimulation of androgen-dependent prostatic diseases. Within the current study, we have undertaken the biochemical evaluation of a number of compounds of varying structural features and which were synthesised within our group as potential enzyme inhibitors in the treatment of androgen-dependent diseases.