OBJECTIVES: Isolated limb perfusion and infusion (ILP/ILI) are therapies for regionally metastatic melanoma where high doses of anticancer drugs are delivered directly into the circulation of an affected limb, while minimizing systemic drug exposure. This procedure can lead to high response rates but without proven benefits to overall survival. It is recommended by ESMO and NCCN guidelines as a treatment option for patients with stage III unresectable metastatic melanoma. However, limited information is available on its use pattern and costs in the literature. This study was to examine patterns of ILP/ILI use and associated costs in patients with melanoma in the US. METHODS: This is a retrospective, observational study using large administrative claims from the MarketScan® databases. Patients who underwent ILP/ILI (CPT-4: 36823) with diagnosis of melanoma (ICD-9-CM: 172.xx, V10.82) between 1/1/2002 and 3/31/2013 were included. Patient characteristics, use patterns, hospital length of stay, and costs (2013 US $) of ILP/ILI were assessed. RESULTS: A total of 113 patients met the study criteria and were included in the analysis. The mean age was 62.1 years (standard deviation [SD] 14.1); 39.8% were male.  The mean baseline Charlson’s comorbidity index was 0.24 and 36.4% of patients were Medicare beneficiaries. Overall, 86.4% of patients had melanoma in the lower limb, 12.7% in the upper limb, and 0.9% in both upper and lower limbs; 59.3% had lymph node metastasis and 56.8% had skin metastasis. Four patients (3.5%) underwent multiple ILP/ILI procedures. The mean (±SD) hospital length of stay was 5.6 (± 3.5) days and the mean (±SD) cost was $35,898 (± $26,492) per ILP/ILI procedure. CONCLUSIONS: The use of isolated limb perfusion and infusion was associated with relatively long hospital stay and high cost. The results of this study may provide source data for economic evaluations of treatment options for regionally metastatic melanoma.