Background – Patients with advanced non‐small cell lung cancer (NSCLC) have limited treatment options. Alongside conventional anticancer treatment, additive homeopathy might help to alleviate side effects of conventional therapy. The aim of the present study was to investigate whether additive homeopathy might influence quality of life (QoL) and survival in NSCLC patients. Methods – In this prospective, randomized, placebo‐controlled, double‐blind, three‐arm, multicenter, phase III study, we evaluated the possible effects of additive homeopathic treatment compared to placebo in patients with stage IV NSCLC, with respect to QoL in the two randomized groups and survival time in all three groups. Treated patients visited the university teaching hospital every 9 weeks: 150 patients with stage IV NSCLC were included in the study; 98 received either individualized homeopathic remedies (n = 51) or placebo (n = 47) in a double‐blinded fashion; and 52 control patients without any homeopathic treatment were observed for survival only. The constituents of the different homeopathic remedies were mainly of plant, mineral, or animal origin. The remedies were manufactured by stepwise dilution and succussion, thereby preparing stable GMP grade formulations. Results – QoL as well as functional and symptom scales showed significant improvement in the homeopathy group when compared with placebo after 9 and 18 weeks of homeopathic treatment (p < .001). Median survival time was significantly longer in the homeopathy group (435 days) versus placebo (257 days; p = .010) as well as versus control (228 days; p < .001). Survival rate in the homeopathy group differed significantly from placebo (p = .020) and from control (p < .001). Conclusion – QoL improved significantly in the homeopathy group compared with placebo. In addition, survival was significantly longer in the homeopathy group versus placebo and control. A higher QoL might have contributed to the prolonged survival. The study suggests that homeopathy positively influences not only QoL but also survival. Further studies including other tumor entities are warranted.