Background. Occupational hand eczema is common in hairdressers, owing to wet work and chemicals. Objectives. To estimate whether hairdressers in Denmark have their hand eczema reported as an occupational disease and to clarify the reasons for not reporting. Methods. A register-based study was performed, comprising trained hairdressers (n = 7840), using a self-administered postal questionnaire including questions on hand eczema and it being reported as an occupational disease. A response rate of 67.9% (n = 5324) was obtained. Results. Overall, 2186 respondents ever had hand eczema; 71.3% were apprentices at the time of hand eczema onset. The majority (61.9%) had had hand eczema several times and 21.3% (almost) all of the time, but only 20.7% had reported their hand eczema as being occupational to the National Board of Industrial Injuries (Denmark). A positive association between severity of hand eczema and filing a report was found (odds ratio 19.2; 95% confidence interval 8.18-45.06). The main reasons for not reporting were 'I thought it would eventually get better' (40.4%) and 'My doctor didn't tell me it was possible to report it' (26.6%). Conclusions. Hand eczema is considerably under-reported as an occupational disease; the perception of hand eczema among hairdressers and the lack of reporting from doctors are the main reasons for this.