Anti-cancer immunotherapy is an emerging approach to enhance endogenous tumor-directed immune responses. Dendritic cells (DCs) are of particular interest in this regard due to their exclusive role in cell- mediated immunity. Using versatile poly(D,L-lactic- co-glycolic acid) (PLGA) nanoparticles, multiple vaccine components can be delivered to DCs in a protected and sustained-release manner. Active targeting of DCs in vivo using PLGA nanoparticles decorated with either receptor ligands or specific antibodies can enhance uptake, processing and presentation of antigens to T lymphocytes resulting in immnuostimulation. This opens up novel approaches in nanomedicine for design of cancer vaccines. Since significant progress in cancer vaccination requires immunomonitoring during immunotherapy, PLGA nanoparticles are promising vehicles for directing the molecular imaging probes towards DCs to map their way after being internalized. This approach may elucidate the dynamic of DC activation, fate, DC- T cell interaction in lymph nodes and tumor cells. This vital information would assist in development of vaccine strategies to shift the balance in favour of immune system.