We present three clinical cases that illustrate some of the key features of the diagnosis and management of immune-mediated heparin-induced thrombocytopenia (HIT). The importance of having a high clinical suspicion for HIT in the appropriate clinical setting is emphasized. Early therapeutic decisions should be based on a clinical diagnosis, with laboratory tests serving as confirmation. Low-molecular-weight and unfractionated heparins are to be strictly avoided in patients with HIT. Identification bracelets or necklaces may be useful to reduce inappropriate administration of these agents to patients with HIT presenting with acute coronary syndromes.