Innervation of the extensor and flexor tendons in human fingers has been studied by a whole-mount histochemical enzyme technique, and the findings have been compared with those from sections stained with silver. The flexor tendons in the fingers are well innervated in the region of the vineula, but the remainder of each tendon is sparsely innervated. A free type of nerve ending is more abundant than are organized encapsulated nerve endings. The extensor hood is innervated by a plexus of nerves more abundant over joints and least abundant over the phalanx. The function of these nerve fibers and endings has not been established. The need for study of pathological states by this technique is apparent.