Background <p>Developing critical thinking is important in nursing as it supports basic cognitive processes; however, students may have difficulty developing these skills due to high academic and clinical stress. Social intelligence and stress management are seen as critical for clinical success and quality of care.</p> Aim <p>This study aimed to investigate the effects of a structured critical thinking education course on nursing students’ critical thinking dispositions, social intelligence levels, and nursing education-related stress.</p> Methods <p>A quasi-experimental design with pretest–posttest control groups was employed. The study included 66 first-year undergraduate nursing students. The intervention group received a 14-week structured critical thinking education course.</p> Results <p>Posttest Critical Thinking Disposition Scores were statistically significant from pretest scores (<i>p</i> = .004). No significant changes were seen in the mean scores of Social Intelligence and Nursing Education Stress. There was a moderate positive correlation between Critical Thinking Disposition and the Social Intelligence Scale subscales.</p> Conclusion <p>The findings suggest that integrating critical thinking education into nursing curricula may enhance students’ cognitive and social competencies. While stress levels were not significantly reduced, improved systematic thinking was linked to lower perceived stress, indicating the potential of critical thinking strategies to strengthen essential nursing skills and stress resilience.</p>