Recently, there has been a significant increase in thyroid pathology worldwide. In most studies of thyroid pathology, it is increasingly common to see an increase in thyroid hypofunction among individuals from different population groups. The aim of the study is to investigate the clinical and psychopathological features of the formation and course of anxiety disorders in patients with primary hypothyroidism. It was examined 74 patients of both sexes, aged 30–55 years with primary hypothyroidism (mild – 26.1% of patients, moderate – 45.2%, severe – 28.7%) who were diagnosed with anxiety disorder of organic nature (F06.4). The following examination methods were used in the study: clinical-neurological, clinical-psychopathological, anamnestic, psychodiagnostic. The most common complaints among the examined patients were constant feelings of anxiety, unmotivated anxiety, mood depression, various fears and intrusive memories, loss of interest in previous activities, general weakness, and rapid physical and intellectual fatigue. According to the study results, clinical picture of anxiety disorders in the examined patients is represented by anxious (38.2% of the examined), panic (36.7%) and anxious-depressive (25.1%) variants of psychopathological symptoms. The analysis of the severity of anxiety manifestations using the State-Trait Anxiety Inventory shows that in hypothyroidism there was an increase in the level of situational and personal anxiety. Analysis of neuropsychiatric stress level in the examined patients showed predominance of extensive (excessive) stress in moderate and severe hypothyroidism and intense (moderate) stress in patients with mild hypothyroidism. The data obtained during study allow to develop diagnostic criteria for anxiety disorders in patients with organic and symptomatic mental illnesses due to primary hypothyroidism. Keywords: thyroid gland, neurotic disorders, anxiety, worry.