This systematic review aimed to examine the knowledge of caregivers regarding pressure ulcer (PU) prevention. A thorough, methodical search was conducted from the earliest date to February 1, 2023 using keywords extracted from Medical Subject Headings such as “Caregivers”, “Knowledge”, and “Pressure ulcer” in various international electronic databases such as Scopus, PubMed, Web of Science, and Persian electronic databases such as Iranmedex and Scientific Information Database. The quality of the studies included in this systematic review was evaluated using an appraisal tool for cross‐sectional studies (AXIS tool). In total, 927 caregivers participated in the eight studies. The average age of the participants was 40.50 (SD = 12.67). Among the participants, 61.87% were women. The average caregiver's knowledge of PU prevention was 53.70 (SD = 14.09) out of 100, which suggests a moderate level of knowledge. Factors such as level of education, age, occupation, information about PUs, attitude, and practice had a significant positive relationship with caregivers' knowledge related to the prevention of PUs. Knowledge had a significantly negative relationship with age. In addition, marital status, type of relationship, age, gender, occupation, level of education, and inpatient wards had a significant relationship with caregivers' knowledge regarding PUs prevention. Therefore, managers and policymakers in the medical field can help increase caregivers' knowledge by providing an online or in‐person educational platform relevant to PU prevention.