This study was designed to estimate the incidence of cancer in a random sample of persons in the general Danish population in relation to a personality characteristic measured by the ‘Test of Psychic Vulnerability’. The authors examined the cancer incidence in a cohort of 5136 randomly sampled persons aged > 25 years living in Copenhagen County, Denmark. The responses to questionnaires and the results of examinations, including the Test of Psychic Vulnerability, were collected during 1982–1984 and during 1991–1992. The observed numbers of cancers were compared with the numbers that would have been expected if the cohort members had experienced the same risk of cancer as the population of Copenhagen County. A total of 403 cancers were observed, and 412.02 were expected, yielding a standardised incidence ratio of 0.98 [95% confidence interval (CI) 0.88–1.19]. There was no significant increase in the risk of site-specific cancers. The risk for cancer was not influenced by the type of vulnerability in a multivariate analysis (hazards ratio 1.16; 95% CI 0.85–1.57). The authors concluded that no increased risk for cancer exists among psychically vulnerable persons compared with non-vulnerable persons; however, the results indicate that behaviour and certain lifestyle factors may be determined by personality, which, in turn, may determine the risk for cancer.