The distribution and variability of the nerves innervating the shoulder joint were determined in 25 fresh human adult cadavers using 3.5x magnification for dissection. The results showed that 100% of the specimens had dual innervation of the coracoclavicular ligaments, the subacromial bursa, and the acromioclavicular joint. This dual innervation was from the articular branches of the suprascapular nerve and of the lateral pectoral nerve. Constant relationship of these 2 nerves to bony landmarks will permit anesthetic blocks for diagnosis and possible therapeutic intervention. A consistent pattern of innervation of the posterior and inferior shoulder joints also is described.