As recent clinical and animal studies have indicated, colchicine, with its anti-fibrotic, anti-mitotic and anti-inflammatory activities, has suppressive effects in the pathogenesis of Peyronie's disease. Oral colchicine treatment was initiated in 60 Peyronie's patients during their acute phase (mean duration of disease: 5.7 +/- 4.3 months). Long-term results, based on changes of subjective and objective criteria, were assessed and predictive factors of successful outcome were investigated. After a mean follow-up of 10.7 +/- 4.7 months, the penile deformity improved in 30%, remained unchanged in 48.3% and deteriorated in 21.7%. Pain resolved in 95%. Best results were obtained in those with no risk factor for vascular disease, presenting during the initial 6 months of disease, degree of curvature <30 degrees, no erectile dysfunction by history and positive response to combined injection and stimulation test. In conclusion since tunica albuginea is affected as a whole in Peyronie's disease, systemic oral agents, such as colchicine, may be preferred in the early phase of the disease.