Heparin-induced thrombocytopenia and thrombosis (HIT/T) syndrome is usually triggered by an immune response after repeated administration of heparin. The syndrome is strongly associated with limb deep vein thrombosis and is potentially life-threatening if unrecognized. We describe the case of a patient with compartment syndrome of the left forearm complicated by HIT/T that developed after Port-A-Cath implantation through the left subclavian vein. Prompt recognition of HIT/T, immediate withdrawal of heparin, and timely institution of thrombolytic therapy successfully prevented limb loss.