Summary: Depression is one of the most common chronic health problems in developed countries. Its prevalence increased by more than 18% during the first decades of the 21st century. Among the numerous factors that increase the risk of depression are disturbances in circadian rhythms. The aim of this article is to discuss the importance of chronobiological factors in the treatment of depression and recommendations on the use of agomelatine in the treatment of this disorder. Circadian rhythm is a fundamental physiological process, adapting the functioning of the body to cyclically changing external conditions, and is also a determinant of the body's health by influencing numerous functions, including mood regulation. In addition to pharmacological treatment with agomelatine, chronobiological treatments for depression include behavioural interventions, interpersonal and social rhythm therapy, phototherapy and light avoidance, melatonin therapy and sleep deprivation. Agomelatine is an effective antidepressant with a different mechanism of action from other antidepressants. The drug is particularly indicated for patients who report anxiety, anhedonia, sleep disturbances or poor tolerance of antidepressants in the clinical picture of depression. Compared to other antidepressants, agomelatine has good tolerability and greater patient acceptance of treatment. The use of the drug is associated with a lower risk of bothersome side effects such as weight gain, sexual dysfunction, gastrointestinal disturbances, excessive sweating.