AIM: Cytoreductive nephrectomy is considered beneficial in patients with metastasised kidney cancer but only a minority of these patients undergo cytoreductive surgery. Factors associated with nephrectomy and the independent effect of nephrectomy on survival were evaluated in this study. METHODS: Patients were selected from the population-based cancer registry and detailed data were retrieved from clinical files. Factors associated with nephrectomy were evaluated by logistic regression analyses. Cox proportional hazard regression analysis was performed to evaluate factors associated with survival; a propensity score reflecting the probability of being treated surgically was included in order to adjust for confounding by indication. RESULTS: 37.5% of 328 patients diagnosed with metastatic kidney cancer between 1999 and 2005 underwent nephrectomy. Patients with a low performance score, high age, >/=2 comorbid conditions, >/=2 metastases, low or high BMI, weight loss, elevated lactate dehydrogenase, elevated alkaline phosphatase, female gender and liver or bone metastases were less likely to be treated surgically. Three year survival was 25% and 4% for patients with and without nephrectomy, respectively (p