Dexamethasone effectively decreases the incidence of nausea and vomiting among pediatric and adult patients. In this study, we evaluated the effects of single-dose dexamethasone on wound healing in a prospective, randomized, experimental animal model. Anesthesia was induced with thiopental 100 mg/kg intraperitoneally. Dexamethasone 1 mg/kg was administered intraperitoneally in a dexamethasone group, and physiological saline was administered in a control group. Collagenization, epithelization, and fibroblast content were significantly less in the dexamethasone group compared with the control group (P values of 0.002, 0.041, and 0.023, respectively). The vascularity and the degree of inflammatory cells were more intense in the dexamethasone group compared with the control group (P values of 0.023 and 0.002, respectively). The white blood cell count was similar in the control (7.84 ± 2.09) and dexamethasone (6.98 ± 2.12) groups. The mean hydroxyproline level was 0.72 ± 0.13 mg/g in the dexamethasone and 1.03 ± 0.19 mg/g in the control group. Hydroxyproline levels were significantly less in the dexamethasone group (P = 0.001). We conclude that dexamethasone at 1 mg/kg may have negative effects on wound healing.