Introduction: Regulatory agency approval of a drug signifies that the drug’s benefits outweigh the risks of administration. Intravenous immunoglobulin (IVIg) has been approved for some indications, but its use also extends to other off-label (non-approved) indications. This study analyzes the use and cost associated with IVIg treatment in a healthcare institution Methods: Descriptive, observational, cross-sectional, drug-utilization study. The study evaluates pattern, determinants of use, and costs of treatment with IVIg, comparing approved and off-label indications. Results: 66 patients were included. The most frequent indications of use were Guillain-Barré syndrome (50%) and immune thrombocytopenic purpura (22.7%). Ten (10) patients received IVIg for off-label indications, most frequently polymyositis/dermatomyositis (10.6%). A total of 156 individual prescriptions were registered, 45 of them off-label indications. The INVIMA (Instituto Nacional de Vigilancia de Medicamentos y Alimentos, in Colombia) off-label administrations had a higher cost compared to approved ones ($16,713,213 vs $8,383,855, p<0.001). Similar results were found when comparing costs with FDA and EMA-approved indications ($13,881,994 vs 9,570,488, p: 0,015). Conclusion: Approximately a third of IVIg administrations are outside indications approved by regulatory agencies. Costs of off-label IVIg indications were significantly higher than approved ones. Consensus among agencies is required regarding IVIg, especially in off-label indications.