The blood supply of the lumbrical muscles was studied in 100 upper extremities from fresh human cadavers. Layer by layer dissection revealed the existence of different types of vascularity for the four muscles. The injection of coloured latex or Indian ink solution with gelatin showed the complex arterial network of these muscles together with their various sources of blood supply. Four separate sources of blood supply for each of the muscles were found: the superficial palmar arch (SPA), the common palmar digital artery, the deep palmar arch (DPA) and the dorsal digital artery. It was established that there were no anastomoses between the blood vessels of the tendons of the flexor digitorum profundus muscle and those of the lumbrical muscles. Considerable differences were observed in the details of the blood supply of the individual lumbrical muscles.