Multiple Myeloma (MM) is a hematologic malignancy characterized by clonal plasma cell development, leading to serious complications. Despite traditional treatments, MM remains incurable, necessitating innovative therapeutic approaches. Chimeric Antigen Receptor (CAR) T-cell therapy and Bispecific T-cell engagers (BiTEs) are emerging immunotherapies showing promise in MM treatment. CAR T-cell therapy involves modifying patient T-cells to target specific antigens, primarily B Cell Maturation Antigen (BCMA). BiTEs, on the other hand, are non-IgG-like bispecific antibodies designed to engage both CD3 and tumor-associated antigens. These therapies exhibit impressive efficacy in clinical trials, leading to FDA approvals for specific MM patient populations. Despite their successes, these therapies come with unique challenges and adverse effects, such as cytokine release syndrome (CRS) and neurotoxicity. This narrative review explores the mechanisms, efficacy, challenges, and potential benefits of CAR T-cell and BiTE therapies for MM patients, shedding light on their roles in addressing this complex disease.