This study examines the association between alternative medicines (AM) and cancer survival. A national multicentre study was carried out in Norway in December 1992 to assess the prevalence of AM use among cancer patients. One of the aims of this study was to assess the association between AM and long-time survival. In January 2001, survival data were obtained with a follow-up of 8 years for 515 cancer patients. A total of 112 (22%) assessable patients used AM. During the follow-up period, 350 patients died. Death rates were higher in AM users (79%) than in those who did not use AM (65%). In a Cox regression model adjusted for demographic, disease and treatment factors, the hazard ratio of death for any use of AM compared with no use was 1.30, (95% Confidence Interval (CI) 0.99, 1.70; P=0.056), suggesting that AM use may predict a shorter survival. Sensitivity analyses strengthened the negative association between AM use and survival. AM use had the most detrimental effect in patients with an ECOG (Eastern Cooperative Oncology Group) performance status (PS) of 0 (hazard ratio for use=2.32, 95% CI, 1.44, 3.74, P=0.001), when compared with an ECOG PS of 1 or higher. The use of AM seems to predict a shorter survival from cancer. The effect appears predominantly in patients with a good PS.