OBJECTIVE: To examine the effectiveness of a structured skin care protocol for preventing and treating incontinence-associated dermatitis (IAD) in critically ill patients. METHODS: Participants were drawn from the ICUs of three teaching hospitals between January 2016 and December 2017. Patients were eligible if they were >= 18 years old, had idiopathic fecal incontinence, had diarrhea but were unable to sense it, and were expected to stay in the ICU for at least 72 hours after developing incontinence. A total of 143 patients were enrolled: 79 in the experimental group and 64 in the control group. In the first phase of the study, routine skin care measures were used; in the second phase, three ICU caregivers were trained to provide a structured skin care protocol. Trained research team members conducted the data collection and analysis. The TREND (Transparent Reporting of Evaluations with Nonrandomized Designs) Statement Checklist was followed in reporting the study results. RESULTS: Application of the structured skin care protocol reduced the incidence of IAD from 35.9% in the control phase to 17.7% in the intervention phase (chi(2) = 6.117, P < .05) and also decreased the severity of AD (z = -2.023, P < .05). Further, IAD developed later (z = 2.116, P < .05) in the intervention group than in the control group. In addition, the nursing times to prevent or manage IAD did not differ significantly between the groups (t = -0.258, P > .05; t = -1.190, P > .05). CONCLUSIONS: Use of the developed structured skin care protocol for IAD in critically ill patients lowered the incidence and severity of AD and delayed AD development.