Chimeric antigen receptor (CAR) T cell therapy has revolutionized cancer immunotherapy, particularly for hematological malignancies. This personalized approach is based on genetically engineering T cells derived from the patient to target antigens expressed-among others-on malignant cells. Nowadays they offer new hope where conventional therapies, such as chemotherapy and radiation, have often failed. Since the first FDA approval in 2017, CAR T cell therapy has rapidly expanded, proving highly effective against previously refractory diseases with otherwise a dismal outcome. Despite its promise, CAR T cell therapy continues to face significant challenges, including complex manufacturing, the management of toxicities, resistance mechanisms that impact long-term efficacy, and limited access as well as high costs, which continue to shape ongoing research and clinical applications. This review aims to provide an overview of CAR T cell therapy, including its fundamental concepts, clinical applications, current challenges, and future directions in hematological malignancies.