Aim. Circadian rhythm sleep-wake disorders (CRSWD) are a group of disorders, in which the timing of sleep and wakefulness significantly differs from a patient’s expectations or socially acceptable times. The aimof the article is to present the current principles for the diagnosis and treatment of CRSWD in adults and children. Method. Guidelines proposed as CRSWD treatment standard are based on the recommendations from the scientific societies involved in the sleep research and medicine. Researchers participating in the guidelines preparation were invited by the Polish Sleep Research Society and the Section of Biological Psychiatry of the Polish Psychiatric Association based on their significant contribution to the circadian rhythm research and/or clinical experience in the treatment of these disorders. Finally, the guidelines were adjusted to the questions and comments given by the members of both Societies. Results. Patients with endogenous CRSWD are often misdiagnosed and treated for insomnia or hypersomnia. Therefore, each patient reporting sleep-wake disorders should be interviewed about the quality of sleep and its timing during free days (e.g. weekends, holidays). Avalid CRSWD diagnosis can be also established by using sleep diaries/logs and actigraphy. The treatment of choice for CRSWD is chronotherapy, which involves melatonin application, light therapy, and behavioral interventions. Sleep disorders associated with shift work and time zone changes are a growing health problem. Interventions for these disorders should primarily focus on prevention. Conclusions. The main problem in the treatment of CRSWD is an invalid diagnosis. Hypnotics and/or psychostimulants are often used instead of chronotherapeutic interventions, what can alleviate symptoms but is not an effective treatment.