Dermatitis among hairdressers has been recognized as a significant occupational health problem but the occurrence, contributing factors, and control measures have not been comprehensively studied or reported. Consequently, an epidemiologic field study of dermatitis among hairdressers and its relationship to medical history of allergy, frequency of specific product use, sex, and number of years in hairdressing was conduted in the winter of 1982 in four southern New Jersey counties. Work practices and procedures were observed and chemical Inventories taken during on-site visits to the participants' beauty salons. The data collected were complied and analyzed using a computerized log-linear statistical procedure. The association between the occurrence of dermatitis and a medically confirmed history of allergy is highly significant (p<.001) and decreases with increasing numbers of years in hairdressing, indicating perhaps that highly susceptible individuals leave their jobs. There was no significant relationship between dermatitis and the levels of frequency of product use. Means of controlling and preventing occupational dermatitis among hairdressers are discussed. Because of the complexity and diversity of the chemical products used, further research is needed to explore the specific etiological factors of hairdresser's dermatitis.