Epidemiological studies on pressure ulcers (PUs) in hospitalised infants are scarce. Spain lacks comprehensive research studies providing data on the prevalence or incidence in this population. This work was developed to determine the incidence of PUs in hospitalised infants admitted to intensive and intermediate care units, along with relevant risk factors and preventive measures. A prospective study appraising the incidence of PUs in infants was performed. The risk factors and preventive measures were evaluated using a multivariate logistic regression model. A sample of 268 infants was included. The cumulative incidence of PUs was 12.70% (95% confidence interval, CI = [8.95%-17.28%]). The cumulative incidence in the intermediate care units was 1.90% (CI = [0.39%-5.45%]), while it was 28.18% (CI = [20.02%-37.56%]) in the intensive care units. The PUs were categorised as stage I, 57.10%; stage II, 31.70%; and stage III, 11.10%. The multivariate analysis found the following to be risk factors: low scores in the Spanish version of the Neonatal Skin Risk Assessment Scale (e-NSRAS) (Relative Risk (RR) 0.80; CI = [0.66-0.97]), the use of non-invasive mechanical ventilation (RR 12.24; CI = [4.02-37.32]), and the length of stay (RR 1.08; CI = [1.02-1.15]), suggesting a direct impact of these factors on PU development in infants. Kangaroo care influenced the prevention of PUs (RR 0.26; CI = [0.09-0.71]). The infants admitted in intermediate care units suffered PUs. In the case of intensive care units, the incidence is even higher. The risk increases with the length of stay, while the presence of medical devices, particularly non-invasive mechanical ventilation, is the main causal relationship. Kangaroo care has been shown to be an important preventive measure.