Purpose: We analyzed data from the placebo arm of the MTOPS trial to determine clinical predictors of BPH progression. Materials and Methods: A total of 3,047 patients with LUTS were randomized to either placebo, doxazosin (4 to 8 mg), finasteride (5 mg), or a combination of doxazosin and finasteride. Average length of follow up was 4.5 years. The primary outcome was time to overall clinical progression of BPH, defined as either a confirmed 4-point or greater increase in AUA SS, acute urinary retention, incontinence, renal insufficiency, or recurrent urinary tract infection. We analyzed BPH progression event data from the 737 men who were randomized to placebo. Results: The rate of overall clinical progression of BPH events in the placebo group was 4.5 per 100 person-years, for a cumulative incidence (among men who had at least 4 years of followup data) of 17%. The risk of BPH progression was significantly greater in patients on placebo with a baseline TPV of 31 ml or greater vs less than 31 ml (p Conclusions: Among men in the placebo arm, baseline TPV, PSA, Qmax, PVR and age were important predictors of the risk of clinical progression of BPH.