The aim of this study was to investigate the antiandrogenic activity of a new monoester of cortexolone, cortexolone 17alpha-propionate (CAS 19608-29-8, CB-03-01). Although the compound displayed a strong local antiandrogenic activity in hamster's flank organ test, it did not exhibit antiandrogenic activity in rats after subcutaneous injection, nor did it affect gonadotropins hypersecretion when injected to parabiotic rats. As topical antiandrogen, the steroid resulted about 4 times more active than progesterone (CAS 57-83-0) and, when compared to known antiandrogen standards, it was about 3 times more potent than flutamide (CAS 13311-84-7), about 2 times more effective than finasteride (CAS 98319-26-7) and approximately as active as cyproterone acetate (CAS 427-51-0). Its pharmacological activity seemed to be primarily related to its ability to antagonistically compete at androgen receptor level; nevertheless its primary pharmacological target needs to be further investigated. Its topical activity, along with the apparent absence of systemic effects, anticipates this compound to have the potential of representing a novel and safe therapeutic approach for androgen-dependent skin disorders.