Background: Hand dermatitis, including irritant and allergic contact dermatitis (ACD), is common. Objective: To evaluate allergens, relevant irritants, sources and occupations associated with hand contact dermatitis using North American Contact Dermatitis Group (NACDG) data. Methods: A cross-sectional analysis of 22,025 patients patch tested between 1994 and 2004. Results: Hand involvement was found in 6953 patients; 959 had ACD as the only diagnosis. In these 959 patients, the 12 most frequent relevant allergens were quaternium-15 (16.5%), formaldehyde (13.0%), nickel sulfate (12.2%), fragrance mix (11.3%), thiuram mix (10.2%), balsam of Peru (9.6%), carba mix (7.8%), neomycin sulfate (7.7%), bacitracin (7.4%), methyldibromoglutaronitrile/phenoxyethanol 2.0% (7.4%), cobalt chloride (6.5%), and methyldibromoglutaronitrile/phenoxyethanol 2.5% (6.3%). Rubber allergens were most commonly associated with occupation. One third of patients with hand ACD had identifiable relevant irritants. Limitations: Cross-sectional analyses prevent evaluation of causal associations. Conclusion: In NACDG patients with hand ACD, the most common allergens included preservatives, metals, fragrances, topical antibiotics, and rubber additives.