To improve patient outcomes during emergent situations, nurses require strong clinical judgment to recognize, assess, and intervene to make appropriate decisions. Unfortunately, it can be challenging to provide nursing students with the necessary knowledge to utilize skills such as clinical judgment in complex emergency situations. Limited access to clinical experiences, particularly in oncology, leaves many students unprepared to manage deteriorating patients after graduation. Virtual simulation has emerged as a promising educational strategy, enabling students to apply knowledge, develop critical thinking skills, and gain competence in a safe environment. This mixed-methods study evaluated the impact of a virtual simulation on nursing students’ clinical judgment during patient deterioration in oncology. Quantitative assessments measured changes in clinical judgment before, during, and after the simulation, while a qualitative reflective questionnaire captured students' insights into their decision-making processes. Quantitative data demonstrated improvements in students' decision-making abilities, particularly in recognizing and addressing early signs of patient deterioration in oncology. Qualitative responses indicated that students felt more confident and better able to bridge theoretical knowledge with clinical practice, an essential outcome for building clinical decision making. Findings from this study suggest that virtual simulation may enhance nursing students' clinical judgment by providing a structured and safe environment for skill development. The results support virtual simulation as a practical approach for strengthening the development of clinical judgment in nursing education, advancing patient safety, and improving quality of care in oncology nursing.