The present study aims at defining the economic and organizational impacts of the introduction of chimeric antigen receptor T-cell therapy (CAR-T) in Italy, for the management of diffuse large B-cell lymphoma (DLBCL) patients in third-line therapy, defining the overall level of sustainability for both hospitals and the National Healthcare System (NHS). The analysis focused on CAR-T and Best Salvage Care (in the following BSC), assuming the Italian hospital and NHS perspectives, over a 36-month time horizon. Process mapping and activity-based costing methodologies were applied to collect the hospital costs related to the BSC and CAR-T pathways, including adverse event management. Anonymous administrative data on services provided (diagnostic and laboratory examinations, hospitalizations, outpatient procedures, and therapies) to 47 third-line patients with lymphoma, as well as any organizational investments required, were collected, in two different Italian Hospitals. The economic results showed that the BSC clinical pathway required less resources in comparison with CAR-T (excluding the cost related to the therapy) (BSC: 29,558.41 vs. CAR-T: EUR 71,220.84, −58.5%). The budget impact analysis depicts that the introduction of CAR-T would generate an increase in costs ranging from 15% to 23%, without considering treatment costs. The assessment of the organizational impact reveals that the introduction of CAR-T therapy would require additional investments equal to a minimum of EUR 15,500 to a maximum of EUR 100,897.49, from the hospital perspective. Results show new economic evidence for healthcare decision makers, to optimize the appropriateness of resource allocation. The present analysis suggests the need to introduce a specific reimbursement tariff, both at the hospital and at NHS levels, since no consensus exists, at least in the Italian setting, concerning the proper remuneration for the hospitals who guarantee this innovative pathway, assuming high risks related to timely management of adverse events.