Purpose The purpose of this study was to determine the time to development, severity, and risk factors of incontinence-associated dermatitis (IAD) among critically ill patients with fecal incontinence. Subjects and setting Forty-five patients with a mean age of 49.4 ± 18.5 years (mean ± SD) in the surgical/trauma critical care unit (ICU) of 1 of 3 urban hospitals who were free of any perineal skin damage at study start participated in the study. The majority (76%) were male. Methods Surveillance of skin for IAD and chart review of data initially and daily. Results Incontinence-associated dermatitis developed in 36% of patients. The median time to onset of IAD was 4 days (range, 1-6). Eighty-one percent of patients still had IAD at discharge from the ICU and at the end of their surveillance (median time = 7 days, range, 1-19 days). The severity of erythema associated with IAD was mild, moderate, or severe for 13%, 11%, or 4% (means) of the time patients were observed. Denudement occurred 9% of the observed time. Frequent incontinence of loose or liquid stools and diminished cognitive awareness were significant independent risk factors for development of IAD sooner. Conclusion Incontinence-associated dermatitis develops in critically ill patients with fecal incontinence relatively quickly and does not resolve in most before their discharge from the ICU. Early monitoring and prevention of IAD, especially in patients with diminished cognition or with frequent leakage of loose or liquid feces, are recommended to promote skin health.