A 23 year old woman who presented with severe acne had been treated with 40 mg/day isotretinoin. On her monthly control, severe cheilitis and bilateral toe nail onycholysis were observed. It is well known that systemic retinoids have several side effects. Although dystropic nail, paronichia-like changes, median nail dystrophy have previously been reported with isotretinoin therapy, onycholysis is rare. In this report, we describe a case with isotretinoin induced nail fragility and onycholysis.