Weakness of the hand is a common problem in the elderly. When joint and vascular diseases have been ruled out, a systematic anatomic approach to the possible neurologic causes can be used to sort through nonspecific symptoms and the complexity of hand anatomy. Syndromes of the peripheral nerves supplying the hand (ie, median, ulnar, radial) are common and are generally caused by compression of these nerves in their pathway through the elbow, forearm, or wrist. Other common causes of hand weakness include lower motor neuron syndromes involving the brachial plexus; cervical radiculopathy amyotrophic lateral sclerosis; and myasthenia gravis. Along with a careful history and physical examination, several tests are helpful in discerning the nature and location of lesions. Electromyography, magnetic resonance imaging, computed tomography, and myelography may all be used to exclude or support a diagnosis.