Background <p>It is very important to use new teaching methods to improve the skills of classification and assessment of pressure injuries of nursing students who will provide direct care to patients after graduation. This study evaluated the effectiveness of in-situ simulation and moulage in improving nursing students’ pressure injury classification and assessment skills.</p> Methods <p>This randomized controlled trial was completed with 84 senior nursing students. Students participating in the study were randomly assigned to the in-situ simulation, in-laboratory simulation, and control group.</p> Results <p>It was found that students in the in-situ simulation group had significantly higher knowledge test (post-test) scores than the control group (<i>p</i> &lt; 0.05). Students in the in-situ and in- laboratory simulation groups had significantly higher correct classification percentages and performance scores for both laboratory and clinical assessment of pressure injury than students in the control group (<i>p</i> &lt; 0.05).</p> Conclusion <p>Moulage is a useful tool for developing and transferring nursing students’ pressure injury classification and assessment abilities to the clinical setting when used with both in-situ and in-laboratory simulation methods.</p> Trial registration <p>Retrospective registration was completed on ClinicalTrials.gov (NCT06406504, registered on 2024-05-06).</p>