BACKGROUND: Higher rates of suicidal behaviour have been reported among staff in mental health care than in the general population. However, no studies of these two groups have been carried out simultaneously, using the same methods. This study aims to investigate whether they differ in terms of age- and sex-standardized prevalence of suicidal behaviour. METHODS: Identical questions about suicidal behaviour were addressed in the same year to a random sample of the general population and to mental health-care staff in Stockholm. Life weariness among the latter was also investigated. RESULTS: Age- and sex-standardized past year prevalences of suicidal thoughts and suicide attempts were found to be similar among mental health-care staff and the general population. Lifetime prevalence of both suicidal thoughts and suicide attempts was significantly higher among mental health-care staff than among the general population. Psychologists/social workers have a higher probability of: lifetime thoughts of life is not worth living; death wishes; and, suicidal thoughts, than nurses/assistant nurses. CONCLUSIONS: Reports on lifetime prevalence of suicidal behaviour may be biased in populations that are not reminded of these problems in everyday life. Data on past year prevalence of suicidal behaviour show clearly the similarity between the general population and the mental health-care staff.