Pruritus is a natural defence mechanism of the body and creates the scratch reflex as a defensive reaction to potentially dangerous environmental factors. Together with pain, pruritus is a type of superficial sensory experience. Pruritus is a symptom often experienced both in healthy subjects and in those who have symptoms of a disease. In dermatology, pruritus is a frequent symptom associated with a number of dermatoses and is sometimes an auxiliary factor in the diagnostic process. Apart from histamine, the most popular pruritus mediators include tryptase, endothelins, substance P, bradykinin, prostaglandins and acetylcholine. The group of atopic diseases is characterized by the presence of very persistent pruritus. It is found in almost all patients with atopic dermatitis or urticaria. Cutaneous T-cell lymphoma is another group of pruritic diseases where the symptom of pruritus develops at an early stage and becomes intensified as the disease progresses. Other dermatoses include psoriasis, parasitic diseases and also systemic diseases in which pruritus is often the first and the only symptom suggesting an internal health problem. Cases of pruritus in healthy subjects, possibly associated with skin dryness or pregnancy in women, have also been reported. This paper presents mechanisms responsible for pruritus and the most important dermatoses in which this symptom is found. Treatment of pruritic dermatoses is difficult and always requires an interdisciplinary approach. Not all dermatoses can be successfully treated with antihistamine drugs, particularly if patients suffer from cutaneous T-cell lymphoma, liver or kidney diseases. For this reason, the problem of pruritus is the focus of attention of many scientists, and the subject of interdisciplinary studies.