737 patients with suspected cosmetic- or medicament-related contact dermatitis were patch tested with 6 emulsifier agents: triethanolamine, cetyl stearyl alcohol, sorbitan sesquioleate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monooleate, and Amerchol L 101. 39 patients (5.3%) gave 1 or more positive patch tests to emulsifiers. A total of 54 positive reactions were found, 23 of which were clinically relevant, triethanolamine being the most frequent sensitizer. Patients with emulsifier sensitivity generally give a high prevalence of positive patch tests to other common ingredients of topical preparations, such as preservatives or active ingredients. Cosmetics and topical medicaments were detected as the source of sensitization in an equal number of patients. Patch tests with patients' own causative preparations were frequently negative. To avoid overlooking emulsifier sensitivity, it is advisable to test these compounds in patients with contact dermatitis that is possibly due to topical preparations, regardless of whether they have other clinically relevant positive reactions or whether patch tests with their own products are negative.