A pressure ulcer is a localized skin injury and underlying tissue, usually as a result of friction or pressure against the surface of the skin. The global mortality rate of pressure ulcers was above 60% for hospitalized patients who wait 1 year of hospital stay. Nurses are the primary responsible body and forefront line care providers for the prevention of pressure ulcers, so nurses’ knowledge and practices are the major rollers to handling this preventable problem. Objective: To assess pressure ulcer prevention knowledge, practices, and their associated factors among nurses in Gurage Zone Hospitals, South Ethiopia, 2021. Methods: A cross-sectional study was conducted in Gurage Zone hospitals from May to June 2021. Data were collected using a structured self-administered paper questionnaire from 372 participants using a simple random sampling procedure, and the collected data were checked for their completeness and entered into Epi-data version 4.6 and exported to SPSS version 26 for analysis. Results: In this study, 176 (49%) of nurses have good knowledge and 210 (58.5 %) of nurses have good practices. Variables having masters and above (adjusted odds ratio = 2.075; confidence interval: 1.886, 4.861), using guideline (adjusted odds ratio = 1.617; confidence interval: 1.017, 2.572), and cooperativeness of patients (1.859; confidence interval: 1.066, 3.242) was significantly associated with nurses prevention knowledge. Being divorced (adjusted odds ratio = 3.002; confidence interval: 1.023, 4.219), degree nurse (adjusted odds ratio = 2.639; confidence interval: 1.388, 3.051), workload (adjusted odds ratio = 0.480; confidence interval: 0.245–0.939), unproportioned nurse to patient ratio (adjusted odds ratio = 0.480; confidence interval: 0.158–0.747), patient cooperativeness (adjusted odds ratio = 1.859; confidence interval: 1.066–3.242), and nurses having good knowledge (adjusted odds ratio = 1.684; confidence interval: 1.078–2.632) statistically significant with prevention practices. Conclusion: The overall level of pressure ulcer prevention knowledge and practice of nurses were good. Qualification of nurses’ degree and above, use of pressure ulcer prevention guidelines, over workload, unproportionate nurse-to-patient ratio, and patient cooperativeness were statistically significant factors for pressure ulcer prevention knowledge and practices. Therefore, health managers should provide continuous professional development, and ensure proportionated nurse-to-patient ratio allocation policy.