Silicone adhesive multilayer foam dressings are used as adjuvant therapy to prevent hospital-acquired pressure ulcers (PUs).Determine if silicone foam dressings in addition to standard prevention reduce PU incidence category 2 or worse compared to standard prevention alone.Multicentre, randomised controlled, medical device trial conducted in eight Belgian hospitals. At risk adult patients were centrally randomised (n=1633) to study groups based on a 1:1:1 allocation: experimental group 1 (n=542) and 2 (n=545) - pooled as the treatment group - and the control group (n=546). Experimental groups received PU prevention according to hospital protocol, and a silicone foam dressing on these body sites. The control group received standard of care. The primary endpoint was the incidence of a new PU category 2 or worse at these body sites.In the intention-to-treat population (n=1605); 4.0% of patients developed PUs category 2 or worse in the treatment group and 6.3% in the control group (RR=0.64, 95% CI 0.41 to 0.99, P=0.04). Sacral PUs were observed in 2.8% and 4.8% of the patients in the treatment group and the control group, respectively (RR=0.59, 95% CI 0.35 to 0.98, P=0.04). Heel PUs occurred in 1.4% and 1.9% of patients in the treatment and control group respectively (RR=0.76, 95% CI 0.34 to 1.68, P=0.49).Silicone foam dressings reduce the incidence of PUs category 2 or worse in hospitalised at-risk patients when used in addition to standard of care. Results show a decrease for sacrum, but no statistical difference for heel/trochanter areas.