This quasi-experimental study aimed to evaluate the effects of sunflower oil and olive oil on the development of diaper dermatitis in hospitalized infants receiving antibiotic therapy. Infants aged 0-24 months were assigned to sunflower oil, olive oil, and control groups. Oils were applied to the diaper area after each diaper change. Infants were followed daily for 3-7 days, and diaper dermatitis severity was assessed using a four-stage clinical classification. The incidence of diaper dermatitis was compared between groups.