Immunomodulatory agents play a crucial role in drug delivery by modulating the immune system's response to therapeutic agents, thereby enhancing treatment efficacy and safety. These agents can either stimulate the immune system to improve drug effectiveness, particularly in cancer and infectious diseases, or suppress it to prevent adverse reactions in conditions like organ transplantation and autoimmune diseases. The integration of immunomodulatory agents into drug delivery systems (DDS) enhances drug targeting, controls release, and optimizes pharmacokinetics. Advanced carriers such as nanoparticles and liposomes are employed to precisely deliver these agents, aligning with personalized medicine approaches to tailor treatments based on individual immune profiles. Despite their potential, challenges such as balancing immune modulation and addressing safety concerns remain. Ongoing research is focused on developing innovative DDS, improving targeting strategies, and identifying new immunomodulatory compounds to address these challenges. This abstract provides an overview of the role and impact of immunomodulatory agents in drug delivery systems and highlights the current trends and future directions in this evolving field.