The aim of the current national survey of all general practitioners (GPs) practising in Norway was to explore assessment, treatment practice and perceived efficacy of treatment of sleep problems in general practice. A short questionnaire, including self-report measures of the frequency and routines of treatment and assessment of sleep problems, was sent to all 4049 GPs in Norway, of whom 1465 (36.7%) provided valid responses. The prevalence of sleep problems among patients in general practice was estimated to be 11.2%, of which almost two-thirds were believed to be caused by a medical condition. Anamnestic information and blood tests were the most common assessment of sleep problems, whereas GPs rarely referred patients to all-night polysomnographic recording. Sleep hygiene advices were the most commonly used treatment strategy, whereas hypnotics were believed to have the best short-term efficacy. Antidepressives were considered to be the best option for long-term management of sleep problems. About one-third of the patients were prescribed benzodiazepines or 'Z-drugs' for more than 6 months. This study demonstrates that sleep problems are recognized by GPs, but despite evidence that non-pharmacological treatment is superior in the long-term management of insomnia, the current study shows that hypnotics are still considered by GPs to be the most successful treatment.