Allergic contact dermatitis has been considered the most common of the many dermatologic conditions found with eyelid dermatitis. This is a retrospective study of 203 patients who presented with persistent or recurrent eyelid dermatitis with or without dermatitis elsewhere. Almost all underwent patch testing and, when indicated, radioallergosorbent test, skin prick and intradermal tests, and in many cases, usage tests as part of the workup. Relevant allergic contact dermatitis was found in 151 of 203 patients (74.%): 46 (23.%) had protein contact dermatitis, but only 7% had protein contact dermatitis without concurrent allergic contact dermatitis. Less than 1% had irritant dermatitis alone. Twenty-three patients had atopic eczema, of whom 16 also had allergic contact dermatitis, protein contact dermatitis, or both. Other conditions included seborrheic dermatitis (n = 11), psoriasis (n = 7), dry eyes (n = 9), and dermatomyositis or overlapping connective tissue disease (n = 7). Important sources of contact sensitivity include cosmetics, metals, topical medications including corticosteroids, eye medications, dust mites, animal dander, and artificial nails; only 5 cases were caused by nail lacquer. Eyelid dermatitis is a multifaceted clinical problem, but in this group of patients, allergic contact dermatitis was a common cause, even among those with atopic eczema. (J Am Acad Dermatol 2002;47:755-65.)