Background:Polydactyly belongs to skeletal anomalies and may be a symptom of more complex genetic syndromes.Main observation:We observed an index case of ulnar hexadactyly of all four limbs in a 20-year-old man from India with three more brothersaffected in his family. No additional anomalies were observed. The diagnosis of a sporadic (ulnar) postaxial hexadactyly was made.Conclusion:Sporadic postaxial hexadactyly is one of the most common polydactylies in humans. In contrast, in the dermatologic literature the condition has only rarely been described.Conclusion:Presence of supernummary digits or toes, i.e. polydactyly, is seen occasionally in the dermatologic practise. The present case is extraordinary since all limbs were involved and the same was true for three of his brothers. If treatment is asked, hand surgery would be necessary.