Objective: To determine the relationship between personal, hormonal and lifestyle risk factors and surgically treated benign prostatic hyperplasia (BPH).Materials and methods: A population-based case-control study was conducted in Western Australia (WA) on men aged 40-75 years who were surgically treated at public and private hospitals for BPH during 2001-2002. Controls were recruited from the WA electoral roll Cases and controls were compared with regard to demographic and Lifestyle factors and proxy measures of hormonal status using logistic regression. Data were available for 398 cases and 471 controls.Results: No associations with BPH were found for family history of prostate cancer in father or brother, serving in the military in a combat area, pattern of baldness, smoking status, obesity, alcohol intake and occupational physical activity. The only inverse relationship was observed with heavy alcohol drinking (>30g/day), however, this was not statistically significant. An increased risk of BPH, not statistically significant, was observed for British-born men compared to Australian born and for history of vasectomy. The analysis was repeated after excluding 28% of controls with moderate and severe symptoms of BPH and 7% of cases with mild symptoms prior to surgery, and our results remained essentially unchanged.Conclusions: The results suggest that there are few risk factors for BPH although perhaps country of birth, vasectomy and heavy alcohol consumption may be considered further. (c) 2007 The Royal Institute of Public Health. Published by Elsevier Ltd. All rights reserved.