ObjectivesIt has been reported that maintaining a normal body temperature among surgical patients can reduce the length of hospitalisation by up to 40%, decrease the risk of surgical site infection by 64% and reduce mortality by fourfold. Nurses are primarily responsible for preventing the occurrence of hypothermia among surgical patients. This study assessed nurses’ knowledge and practices with respect to perioperative hypothermia prevention in Northwest Ethiopia, and investigated the factors associated with good knowledge and practice.DesignCross-sectional study.SettingNorthwest Amhara Regional State Referral Hospitals, Northwest Ethiopia, 25 March–20 May 2021.Participants413 nurses working in the perioperative units of five referral hospitals.Outcome measuresPerioperative hypothermia prevention knowledge and practice among nurses.ResultsNearly three-fifths (59.1%; 95% CI: 54.7% to 63.7%) of respondents had good knowledge and about half (50.4%; 95% CI: 45.5% to 55.0%) had good practice with respect to perioperative hypothermia prevention. Factors associated with nurses’ knowledge of prevention of perioperative hypothermia included male sex (adjusted OR (AOR): 1.61, 95% CI: 1.02 to 2.53), having a bachelor’s degree (AOR: 2.50, 95% CI: 1.25 to 5.00), having a master’s degree (AOR: 4.39, 95% CI: 1.45 to 13.20) and training participation (AOR: 3.68, 95% CI: 2.14 to 6.33). Factors associated with nurses’ practice of prevention of perioperative hypothermia included working in recovery (AOR: 2.87, 95% CI: 1.08 to 7.58) and intensive care units (AOR: 2.39, 95% CI: 1.09 to 5.22), training participation (AOR: 2.64, 95% CI: 1.53 to 4.57), being satisfied with their job (AOR: 2.15, 95% CI: 1.34 to 3.43) and having good knowledge (AOR: 2.64, 95% CI: 1.63 to 4.27).ConclusionNurses’ knowledge and practice of the prevention of perioperative hypothermia were inadequate. Hospital managers need to design and strengthen training programmes and work to enhance job satisfaction.