A major use of the of the internet is for health information-seeking. There has been little research into its use in relation to mental health. To investigate the prevalence of internet use for mental health information-seeking and its relative importance as a mental health information source. General population survey. Questions covered internet use, past psychiatric history and the 12-item General Health Questionnaire. Eighteen per cent of all internet users had used the internet for information related to mental health. The prevalence was higher among those with a past history of mental health problems and those with current psychological distress. Only 12% of respondents selected the internet as one of the three most accurate sources of information, compared with 24% who responded that it was one of the three sources they would use. The internet has a significant role in mental health information-seeking. The internet is used more than it is trusted.