Today's living conditions have changed eating and feeding habits. People have directed to foods considered to be healthy that are grown in natural environment, without additives. However, such eating and feeding habits and orthorexia trends can lead to an unhealthy condition over time. The incidence of orthorexia nervosa (ON), known as a healthy eating obsession, is increasing all over the world. Life-threatening ON can cause serious complications. The etiology, clinical presentation, and treatment of ON, which are not yet included in the diagnosis classifications, are not fully known.There is a need to determine the diagnostic criteria of ON and its relationship with other psychiatric disorders. Especially, the identification of high-risk groups and early interventions can be lifesaving. In this study, a 56-year-old female patient who was followed up in our psychiatry outpatient clinic with diagnoses of major depressive disorder (MDD) and obsessive-compulsive disorder (OCD) and detected ON symptoms during her follow-up was presented in the light of the literature findings. It is noteworthy that the patient's eating and feeding habits, which have changed in the name of healthy nutrition, have deteriorated interpersonal relationships and significant weight loss, especially in recent years. It is important that clinicians are sensitive to ON