We report a rare case of allergic contact dermatitis due to an extract of rosemary (Rosmarinus officinalis). A 23-year-old woman had begun to notice itchy erythema on her face around one month before presentation. She used various cosmetics and a cleansing gel containing rosemary leaf extract. From the patch test results, she reacted positively to the cleansing gel (1% in distilled water) and the rosemary leaf extract (0.1% in distilled water), one of its ingredients.