The invention provides a composition and method for treating benign prostatic hypertropy in mammals so as to cause the dissolution and regression of hypertrophied prostatic tissue and thereby provide relief from the obstructive symptoms associated with the disease. The present composition preferably comprises a sterile pyrogen-free solution of the hydrolytic enzymes collagenase and hyaluronidase, a nonionic surfactant, and an antibiotic; all provided, in a pharmaceutically acceptable, buffered, isotonic, aqueous carrier. The present method preferably comprises the direct intraprostatic injection of a safe and therapeutically effective dose of the composition via the transurethral route of administration.