Purpose: The purpose of this study was to provide longitudinal prevalence rates of incontinence-associated dermatitis (IAD) in patients in an intensive care unit (ICU) and to identify patient characteristics associated with IAD development. Design: Prospective observational. Subjects and Setting: The sample comprised 351 patients aged 18 years and older in a major metropolitan public hospital ICU in Queensland, Australia. Methods: All consenting, eligible participants at risk of developing IAD underwent weekly skin inspections to determine the presence of IAD. Data were collected weekly for 52 consecutive weeks. Descriptive statistics described the study sample and logistic regression analysis was used to identify patient characteristics associated with development of IAD. Results: The weekly IAD prevalence ranged between 0% and 70%, with IAD developing in 17% (n = 59/351) of ICU patients. The odds of IAD developing increased statistically significantly with increasing age (odds ratio [OR]: 1.029, 95% confidence interval [CI]: 1.005-1.054, P =.016), time in the ICU (OR = 1.104; 95% CI: 1.063-1.147, P <.001), and Bristol Stool chart score (OR = 4.363, 95% CI: 2.091-9.106, P <.001). Patients with respiratory (OR = 3.657, 95% CI: 1.399-9.563, P =.008) and sepsis (OR = 3.230, 95% CI: 1.281-8.146, P =.013) diagnoses had increased odds of developing IAD. Conclusions: These data show the high variability of IAD prevalence over a 1-year period. Characteristics associated with the development of IAD in patients in the ICU included older age, longer lengths of ICU stay, incontinent of liquid feces, and having respiratory or sepsis diagnoses.