The aim of this study was to assess the allergenic potential of 0.3% DA-5018 cream, a non-narcotic analgesic agent, using a guinea pig maximization test. Five male and female guinea pigs in the experimental group were sensitized in two steps. First, ,0.3% DA-5018 cream was injected intradermally, and 7 days later, the material was applied topically. After another 2 weeks test material was applied, the skin response was evaluated by visual observation. Five male and female guinea pigs served as cream base group, negative(ultreated) group or positive (2,4-dinitrochlorobenzene, DNCB) group, respectively. 0.3% DA-5018 cream provoked slight erythema in 1 out of 5 cases in male and female guinea pigs sensitized with 0.3% DA-5018 cream or cream base. The animals challenged with cream base also showed slight erythema in 1/5 female guinea pig sensitized with 0.3% 3A-5018 cream or 2/5 male guinea pjgs sensitized with cream base, respectively. Histologically, however, no indication of skin sensitization was observed in all of these cases. The positive control group was sensitized with 0.1% DNCB suspended in olive oil and challenged with 0.01% and 0.1% DNCB ointment, all the animal showed remarkable skin reactions and obvious skin sensitization reactions in a dose dependent manner. From the challenge test it was evident that 0.3% DA-5018 cream did not elicit positive skin reaction interpreted as delayed hypersensitivity reactions, compared with cream base or untreated control group. These findings indicate that allergenic side effects by 0.3% DA-5018 cream is not likely in the clinical use.