A wealth of genomic and proteomic information on microorganisms and parasites, together with recent advances in adjuvant and delivery systems, is being harnessed to develop nanovaccines against infectious and parasitic diseases. The use of nanoparticles in vaccine formulations allows not only improved antigen stability and immunogenicity but also targeted delivery and slow release. However, so far, nanoparticles have not proved capable of surmounting most of the barriers like toxicity issues, clearance from biological system, DNA instability and differences in expression systems. Nevertheless, advances in nanoparticle engineering and understanding of nanoparticle characteristics, is creating new opportunities for the development of nanovaccines as antigen delivery system. This Review focuses on recent progress in development of nanoparticle based antigen delivery vehicles, their use in different diseases, major bottlenecks and challenges to realizing the potential of nanoparticles.