Introduction . The epidemiology of nail apparatus tumours is not well known. They are frequently misdiagnosed because of their uncharacteristic clinical features.

Objective . Evaluation the frequency and nature of nail apparatus tumours in the Northern Polish population.

Material and methods . 1588 patients with various nail apparatus pathology who were diagnosed and treated in the Department of Dermatology, Venerology and Allergology of the Medical University of Gdansk from 2005 to 2010 were included in the study and 129 cases of nail apparatus tumours were diagnosed.

Results . Tumours represent about 8% of nail pathology. In the majority of cases (92%) they are benign. Most frequently melanocytic lesions (41%), osteocartilaginous tumours, fibrous tumours and myxoid pseudocysts were diagnosed. The most common malignant tumour was melanoma.

Conclusions . Nail apparatus tumours in the Northern Poland population are observed quite often. In the majority of cases they are benign. Diagnosis of melanocytic lesions is very important because of risk of melanoma.