Some drugs can cause alterations in the concentration of thyroid hormones in blood even without clinical signs of dysfunction or pathology of the thyroid gland. Apart from the well-known relationship between depression and hypothalamic-pituitary-thyroid (HPT) axis, and the impact of selective serotonin reuptake inhibitors (SSRIs) on thyroid indices, hypothyroidism is a very rare adverse effect of SSRI treatment. However, the case presented here demonstrates that escitalopram may have the potential to induce hypothyroidism without any significant clinical signs and symptoms. Therefore, the possibility of SSRI-induced asymptomatic hypothyroidism presented here may help clinicians in this regard.