The aim of this national cross-sectional study was to explore the prevalence of pressure injuries and incidence of hospital-acquired pressure injuries, and the relating factors in somatic-specialised inpatient care in Finland. The study was conducted in 16 (out of 21) Finnish health care organisations offering specialised health care services. Data were collected in 2018 and 2019 from adult patients (N = 5902) in inpatient, emergency follow-up, and rehabilitation units. Pressure injury prevalence (all stages/categories) was 12.7%, and the incidence of hospital-acquired pressure injuries was 10%. Of the participants, 2.6% had at least one pressure injury at admission. The risk of hospital-acquired pressure injuries was increased for medical patients with a higher age, the inability to move independently, mode of arrival, being underweight, and the absence of a skin assessment or pressure injury risk assessment at admission. For surgical patients, the risk was associated with the inability to move independently, mode of arrival, and lack of skin assessment at admission, while being overweight protected the patients. Overall, medical patients were in greater risk of hospital-acquired pressure injuries than the surgical patients. An assessment of the pressure injury risk and skin status should be carried out more systematically in Finnish acute care hospitals.