By judicious consideration of the clinical appearance, by direct examination with magnification, and by culture results, skin biopsy, and other laboratory results, the clinician is able to diagnose most pathological conditions of the scalp. The scalp participates in many systemic disorders and frequently is the chief site of involvement. Similarly, many generalized disorders limited to the skin exhibit their most typical manifestations in the scalp. Whenever a diagnosis eludes the investigator, more than likely he or she has not considered all of the etiological possibilities or has not pursued an adequate laboratory investigation. A few scalp diseases initially present nonspecific clinical pictures. By utilizing follow-up examinations at appropriate intervals, the diagnosis can eventually be made. Once a diagnosis is made, appropriate treatment will generally produce satisfactory improvement or cure. Nevertheless, a few generally rare conditions will defy the physician's most enlightened and aggressive therapy.