Background <p>Orthorexia nervosa (ON) has gained increasing attention as a potential eating disorder marked by an obsessive preoccupation with healthy eating and strict dietary purity. The condition exhibits notable similarities to obsessive–compulsive disorder (OCD) and obsessive–compulsive personality disorder (OCPD), particularly in terms of perfectionistic tendencies, rigid inflexible thought patterns, excessive conscientiousness, moral inflexibility, and preoccupation with details. The present study sought to determine the prevalence of ON and OCPD traits in a sample of medical students and to evaluate the relationship between these characteristics.</p> Methods <p>This cross-sectional descriptive study included 427 medical students from Ain Shams University (ASU) recruited through convenience sampling. Assessment measures comprised the Düsseldorf Orthorexia Scale (DOS), Personality Diagnostic Questionnaire-4 (PDQ-4), and Personality Inventory for DSM-5 (PID-5) to evaluate OCPD traits.</p> Results <p>The prevalence of ON appeared to affect 8.7% of students, particularly those who exhibit OCPD traits. There was no correlation between ON and participant factors like gender, BMI, or study year. However, the prevalence of ON was significantly higher in academic grades and was positively correlated with high OCPD scores, rigid perfectionism, intimacy avoidance, and perseverance traits.</p> Conclusions <p>Medical students appear to represent a vulnerable population for both ON and OCPD, particularly during the demanding years of medical training. Therefore, screening for orthorexic behaviors among individuals exhibiting OCPD traits is important to enable early identification, timely intervention, and prevention of potential nutritional and psychological complications.</p>