Horner Syndrome is a clinical syndrome caused by disruption of the sympathetic pathway, typically characterized by ipsilateral ptosis, miosis, and facial anhidrosis. Complications can arise during interventional procedures in the thoracic region due to proximity to the upper preganglionic nerve. A 21-year-old female patient who developed drooping of the right eyelid and Horner's syndrome following tube thoracostomy procedure is presented here. It is important to keep in mind that the tube has been removed and the condition may be reversible in terms of treatment.