BACKGROUND Mono(meth)acrylates (monoacrylates and monomethacrylates) are moderate to strong sensitizers. They are used in the production of a great variety of polymers, including nail cosmetics. OBJECTIVE A patient who became occupationally sensitized to photobonded sculptured nails is reported. Detailed patch testing and analyses of the patient's nail cosmetics containing mono(meth)acrylates clarified the cause of her hand and face dermatitis. The current knowledge on mono(meth)acrylates in nail cosmetics is also reviewed. METHODS Patch testings with conventional methods, including patch testing with the patient's own substances, were performed. The patient's nail cosmetics suspected of containing mono(meth)acrylates were analyzed with gas chromatography/mass spectrometry analysis. RESULTS In the (meth)acrylate series, 15 of the 31 (meth)acrylate compounds tested gave an allergic reaction: 2 acrylates, 5 methacrylates, 3 dimethacrylates, and 5 diacrylates. Epoxy diacrylates, cyanoacrylate, triacrylates, and methacrylic acid were negative. Three of seven of her own nail cosmetic preparations contained mono(meth)acrylates as revealed by the gas chromatography/mass spectrometry analysis, and these also gave allergic patch test reactions, namely, the nail liquid, nail hardener, and UV-cured nail gel. CONCLUSIONS The patient probably had been sensitized to the following (meth)acrylate compounds from her nail cosmetics: tripropylene glycol diacrylate and methyl acrylate from her photobonded nail gel; ethyl methacrylate, triethylene glycol dimethacrylate, and methyl methacrylate from her nail liquid; and butyl methacrylate from her nail hardener. She was probably also sensitized to the rare sensitizer aliphatic urethane diacrylate, but the source was not verified. Because nail cosmetics containing mono(meth)acrylates are strong sensitizers, both the workers and the customers should be aware of their sensitizing capacity; they should use no-touch techniques regarding the skin before the mono(meth)acrylates are polymerized.