(1) Background: Improvement in pressure ulcer care depends both on the dissemination of knowledge and its implementation. This study aims to translate the Pressure Ulcer Knowledge Test into Portuguese from Portugal and evaluate the internal consistency of the questionnaire. The second aim is to assess nurses’ pressure ulcer knowledge level. (2) Methods: The Pressure Ulcer Knowledge Test was translated into Portuguese, and the translated test’s internal consistency and content validity were assessed. Further, the authors conducted a cross-sectional survey using the test among 221 nurses working in long-term care units. (3) Results: The Cronbach’s alpha internal coefficient of reliability recorded for the 47 items was 0.738, which is higher than the minimum acceptable level of 0.7. The Cronbach’s alpha for the subscales was 0.709 for prevention/risk and less than 0.5 for staging and wound description. Only two of the 221 nurses achieved a score of 90% correct answers or more. The nurses scored lower in questions related to prevention/risk (Me = 67.4%, IQR = 60.6–75.8% vs. staging: ME = 85.7%, IQR = 71.4–85.7%, description: ME = 85.7%, IQR = 71.4–85.7%, p < 0.001). (4) Conclusion: The internal consistency of the instrument was acceptable. The instrument can accurately measure Portuguese nurses’ knowledge of pressure ulcers, and its information can help improve education and implementation of best practices.