The aim of therapy for benign prostatic hyperplasia (BPH) is to improve quality of life by providing symptom relief and an increased maximum flow rate (Q max), as well as to reduce disease progression and the development of new morbidities. Watchful waiting can be recommended when the International Prostate Symptom Score is ≤7, that is, mild symptoms that do not interfere with daily life activities. The α 1-blockers are an established therapy for BPH and onset of action is rapid, generally within 2 wk of commencing treatment. Intermediate-term benefits can be seen in an improvement in Q max of 10–15% and in symptom scores of 15–20%. The other main medical therapies for BPH are the 5α-reductase inhibitors (5ARIs), which not only reduce symptoms and improve Q max, but also importantly reduce prostate volume. Dutasteride, a dual 5ARI, can provide benefits in symptom score and Q max within 1 mo. The improvements in symptom score and Q max continue up to 4 yr, with stabilisation of prostate volume. In the long-term, unlike α 1-blockers, 5ARIs reduce the risk of BPH progression. The risk of acute urinary retention for men taking dutasteride was reduced by 48% compared with placebo at 2 yr ( p < 0.001) and the risk of BPH-related surgery by 55% ( p < 0.001). The combination of an α 1-blocker and a 5ARI could be considered to provide added benefits over either therapy alone.