Hospital-acquired pressure ulcer (HAPU) is a significant problem in healthcare settings and is associated with negative impacts on patient health. Although monitoring of pressure ulcers (PUs) among hospitalised patients was started more than a decade ago in Oman, no previous studies have been completed to estimate the prevalence and risk factors of HAPUs among patients in the intensive care unit (ICU). The aim of this study was to estimate the prevalence and identify risk factors for HAPUs among adult ICU patients in selected tertiary hospitals in Oman. A retrospective, cross-sectional, nested, case-control design was used to identify the prevalence rate of HAPUs and risk factors for a cohort of adult ICU patients over one calendar year (1 January-31 December 2019) in two tertiary hospitals in Oman. The prevalence rate for HAPU among ICU patients in Oman was 36.4%. However, when excluding cases of stage 1 ulcer, the rate was 30.37%. The most prevalent location was the sacrum (64.1%), and the most common stage was stage 2 (73.1%). The risk factors for HAPU included male sex (odds ratio (OR): 0.37; p=0.023), organ failure (OR: 3.2; p=0.033), cancer (OR: 3.41; p=0.049), cerebrovascular accident (OR: 12.33; p=0.001), mechanical ventilator (OR: 9.64; p=0.025) and ICU length of stay (OR: 1.24; p<0.001). HAPUs among ICU patients constitute a significant problem associated with severe clinical consequences and result in substantial adverse healthcare outcomes worldwide, including in Oman. Identifying the risk factors and the impact on the healthcare system is the foundation for preventing and managing HAPUs.