Immunotherapy of cancer is a promising therapeutic approach which aims to eliminate malignancies by inducing or enhancing an immune response against the tumor. Immunotherapy, however, faces several challenges such as local immunosuppression in the tumor area leading to immunological tolerance. To overcome these challenges, particulate formulations such as nano- and microparticles containing immunotherapeutics have been developed to increase therapeutic efficacy and reduce toxicity of immunotherapy. Particulate formulations based on biodegradable aliphatic polyesters such as poly(lactic-co-glycolic acid) (pLGA) have been extensively used with promising results. In this review, we addressed the potential of pLGA-based particulate formulations for immunotherapy of cancer. The discussion was focused on cancer vaccines and delivery of immunomodulatory antibodies. Features and drawbacks of pLGA systems were discussed together with several examples of recently developed therapeutic cancer vaccines and antibody-loaded particulate systems. Various strategies to overcome the drawbacks and optimize the formulations were given. In conclusion, pLGA-based particulate systems are attractive carriers for development of clinically acceptable formulations in immunotherapy of cancer.