Contact allergy to the UV-absorber 2-(2-hydroxy-5-methylphenyl)benzotriazole (Tinuvin P) was revealed in a patient with wrist dermatitis caused by a plastic watch strap. A high-performance liquid chromatography method was developed and subsequent chemical analysis showed the presence of Tinuvin P in the watch strap. The possibility of cross-reactions between Tinuvin P and various substituted benzotriazole compounds was investigated. No cross-reactions were found.