The objectives of the study were to examine the prevalence of pressure ulcers and hospital-acquired pressure ulcers (HAPU) and identify modifiable factors in patients who develop HAPU as the basis for subsequent quality assurance studies and improvement in hospital care. The study was conducted in five hospitals in two Swedish County Councils. A 1-day prevalence study (n = 1192) using the standards of the European Pressure Ulcer Advisory Panel and Collaborative Alliance for Nursing Outcomes was conducted. The prevalence of ulcers was 14·9% and 11·6% were HAPU. Older age, more days of hospitalisation, less activity, problems with shear and friction and reduced sensory perception contributed significantly to HAPU. Pressure ulcer prevention strategies used more often in those with HAPU were risk assessment at admission, provision of a pressure relief mattress, having a turning schedule and using a heel or chair cushion. The prevalence of pressure ulcers continues to be a significant issue in acute care and the prevalence of HAPU is high. There is significant room for quality improvement in pressure ulcer prevention in Swedish hospitals. Future research needs to address both HAPU and community-acquired pressure ulcers and focus on preventive strategies, including when they are initiated and which are effective in mitigating the high HAPU rate.