Background: In hospitalized patients on bed rest, prolonged immobility has a variety of consequences on the body's various systems and can cause a negative physiologic reaction. Pressure ulcers are a common health problem in immobile patients. Objectives: To assess the risk for developing pressure ulcer among immobilized patients admitted to critical care units, to evaluate the effectiveness of Sensor, Alarm, Nonstress, Nonsensitive, Anti-rashes (SANSAR) diaper on risk for pressure ulcer among immobilized patients, to find out the association between risk for pressure ulcer among immobilized patients and their selected demographic and clinical variables. Methodology: Randomized control trial (RCT) design was adopted for the study. The population of the present study was immobilized patients who are at risk for pressure ulcer. Sixty samples were chosen using power analysis and divided into 30 subjects in each group, demographic and clinical variables were assessed using a structured interview questionnaire and pressure risk assessment for both groups using the Braden scale. Sensor, Alarm, Nonstress, Nonsensitive, Anti-rashes diaper was applied to patients in the experimental group with routine care for one week control group received routine nursing care and posttest was done after one week using Braden Scale. Results: The study results show that posttest mean score in the experimental group was 15.10 ± 1.626 whereas in the control group was 12.50 ± 1.408. Sensor, Alarm, Nonstress, Nonsensitive, Anti-rashes diaper was most effective than the routine care at the p-value 0.001 level. Conclusion: Critically ill patients are at increased risk for acquiring pressure ulcer compared with other hospitalized patients because of the critical illness itself, the preexisting comorbid conditions. The aim of the study was to evaluate the effect of SANSAR diaper on pressure ulcer among immobilized patients admitted to critical care units.