Chlorhexidine is a widely used antiseptic and disinfectant in medical and non-medical environments. Compared to its ubiquitous use, allergic contact dermatitis from chlorhexidine has rarely been reported and so its sensitization rate seems to be low. Chlorhexidine has been used for more than 50 years but it was only in the last two decades, that reports of immediate- type reactions to chlorhexidine were seen. Reactions ranging from localized urticaria to anaphylactic shock and hypersensitivity reactions, including delayed hypersensitivity reactions such as contact dermatitis, fixed drug eruptions, and photosensitivity reactions, began to appear more frequently. However the prevalence of contact urticaria and anaphylaxis due to chlorhexidine remains to be unknown. In this case report we have reported a case of urticaria due to oral use of chlorhexidine. The adverse reaction was confirmed by a skin prick test.