Antinuclear antibodies are used in the diagnosis and evaluation of patients with connective tissue diseases. The study of antinuclear antibodies has also fundamentally expanded our understanding of nuclear anatomy and function. This article reviews the clinically relevant antinuclear antibodies and their disease associations. Developing an understanding of the utilities and limitations of antinuclear antibodies is essential to providing the expert diagnoses prognoses, and care expected of a dermatologist.