Abstract OBJECTIVES Patients with oligometastatic non-small-cell lung cancer (NSCLC) may benefit from therapy with curative intent. Our goal was to identify prognostic factors related to better prognosis in a multicentre analysis of patients who underwent surgery of primary tumours in combination with radical treatment of all metastatic sites. METHODS We retrospectively reviewed the records of oligometastatic patients who underwent resection of primary tumours at 4 centres (August 2001–February 2018). Oligometastasis was defined as ≤5 synchronous metastases in ≤2 organs. Radical metastatic treatment was surgery, radiotherapy or a combination. The Cox proportional hazards model was used for identification of prognostic factors on overall survival. RESULTS We treated 124 patients; 72 (58%) were men, mean age 60 ± 9.8 years, with 87 (70%) adenocarcinoma. Sixty-seven (54%) patients had positive pathologic-N stage (pN). Brain metastases were most common (n = 76; 61%) followed by adrenal (n = 13; 10%) and bone (n = 12; 10%). Systemic therapy was administered in 101 (82%) patients. Median follow-up was 60 months [95% confidence interval (CI) 41–86]. Thirty- and 90-day mortality rates were 0 and 2.4%, respectively. One-, 2-, and 5-year overall survival were 80%, 58% and 36%, respectively. Cox regression analysis showed that patients ≤60 years [hazard ratio (HR) 0.41, 95% CI 0.24, 0.69; P = 0.001] and patients with pN0 (HR 0.38, 95% CI 0.21–0.69; P = 0.002) had a significant survival benefit. The presence of bone metastases negatively affected survival (HR 2.53, 95% CI 1.05–6.09; P = 0.04). CONCLUSIONS Treatment with curative intent of selected oligometastatic NSCLC, including resection of the primary tumour, can be performed safely and with excellent 5-year survival rates, especially in younger patients with pN0 disease.