This article describes a case of Venous Thromboembolism (VTE), was developed in a patient with treatment-resistant schizophrenia. Patient was a 35 years-old female with treatment resistant schizophrenia who was tolerating her residual symptoms of perceptual disturbances. Despite good adherence towards treatment, she never had a complete symptom-free period. Patient also attempted suicide by trying to drown herself at a nearby beach. Considering the suicidal risk and persistency of her psychosis, patient was then initiated on Clozapine therapy. Over a period of 8 weeks, gradual dose increment resulted in an improvement of her symptoms where she was reported to have less frequency of perceptual disturbances. She was reviewed weekly for both her response and tolerability towards the Clozapine treatment. Entering the 11th week of her Clozapine therapy, Patient was admitted into the hospital for left leg tenderness in which she was later treated to be having deep vein thrombosis (DVT). Ultrasound finding revealed long segment thrombus seen from external iliac vein down to popliteal vein of her left lower limb. Patient’s medication dose was maintained at the same dose up until the 16th week of her Clozapine therapy. There were no recurrences or reports of side effects and improvement of sleep patterns were reported by her but her psychotic symptoms still persists. There are always risks and benefits while treating a patient with Clozapine. Clinician should be aware of the risk of deep vein thrombosis (DVT) among treatment resistant schizophrenia patient.