About one-quarter of cases of non- small cell lung cancer are diagnosed sufficiently early, i.e. at stages I to lIlA, to envisage surgical resection. Despite this surgery, the prognosis remains poor. In 2016, what is the harm-benefit balance of chemotherapy in addition to surgical resection of early-stage non-small cell lung cancer? We con- ducted a review of the literature using the standard Prescrire methodology. In 38 trials including about 11 000 patients, the 5-year survival rate rose from 60% to 64% when surgery was followed by chemotherapy in patients who mainly had stage IB or I disease, and from 29% to 33% in patients with mainly stage Ill disease who also received radiation therapy. The chemo- therapy regimens used in most of these trials consisted of cisplatin plus a vinca alkaloid such as vinorelbine. In 15 trials including more than 2000 patients, most of whom had resectable stage IB, IIB or lIlA disease, platinum-based chemotherapy given before surgery raised the 5-year sur- vival rate from 40% without chemo- therapy to 45%. There are too few data to assess the impact of chemotherapy on sur- vival among patients who undergo surgery for stage IA disease. About two-thirds of patients who receive platinum-based chemotherapy experience serious adverse effects, and at least 1% of patients die from toxicity. The most common adverse effects are haematological disorders. Tyrosine kinase inhibitors and angiogenesis inhibitors have not been shown to improve survival among patients with resectable non-small cell lung cancer. Clinical guidelines published since 2010 recommend cisplatin-based chemotherapy for patients with resect- able stage IIB or lIlA disease. There is some disagreement concerning stage IB and IIA disease. In practice, clinical trials show that adjuvant chemotherapy improves the 5-year survival rate by a few percent- age points among patients who under- go surgical resection for non-small cell lung cancer. Adjuvant chemother- apy with cisplatin and a vinca alkaloid is thus a reasonable choice for surgi- cal patients (except those with a local- ised tumour measuring ≤ 3 cm), who accept its toxicity, with the hope of a slightly longer survival. It is also a reasonable option for patients to forgo chemotherapy.