The role of personality characteristics and psychological distress in the occurrence of severe neck trouble was investigated in a 3-year follow-up study conducted from 1984 to 1987 among 1015 men (age: 25-49 years old) employed as machine operators, carpenters and office workers. The subjects had reported in a questionnaire in 1984 that they had experienced no more than 7 days with neck trouble during the past 12 months. Based on a similar questionnaire in 1987, severe neck trouble was defined as trouble having lasted more than 30 days. Psychological distress and personality characteristics were assessed in 1984 by the Middlesex Hospital Questionnaire (MHQ) and the Maudsley Personality Inventory (MPI) respectively. Severe neck trouble occurred in 11% of the subjects, who were considered as cases; those with 0-7 days with neck trouble were considered as controls. When individual and occupational factors were adjusted for no powerful predictors were found. However, after performing a backward stepping analysis, somatic symptoms and hysteria were significantly associated with severe neck trouble. In occupation-specific analyses, somatic symptoms and neuroticism were significantly associated with the occurrence of severe neck trouble among the machine operators, as were somatic symptoms, depression and hysteria among the office workers. Neither the personality characteristics nor psychological distress predicted the occurrence of severe neck trouble among the carpenters. We conclude that the associations between psychological factors and neck trouble are complex and may depend on the psychosocial environment.