The application of combinatorial approaches in conjunction with phage display techniques might be critical for development of vaccines against various infective and cancer diseases. Phage technique allows the generation of novel immunogens representing structural/molecular mimics of pathogen-derived immunodominant epitopes, or protein domains displayed on phages capable of inducing protective antibodies, or construction of novel vaccines based on incorporation of antigenic/genetic variability of pathogens or cancer cells in the context of phage particles. The diversity of applications and success of phage display are due to its simplicity and flexibility along with the possibilities of very cheap large-scale production of phage particles by recovering them from infected bacterial culture supernatants as nearly 100% homogenous preparations. Phages are easy to manage, they resist heat and many organic solvents, chemicals, or other stresses, and, importantly, phage particles are highly immunogenic and do not require adjuvant. Furthermore, phages do not require the cold chain (requirement to store vaccines at refrigerated or frozen temperatures), which equates to lower transport and storage costs. Considering these points, recombinant phages should be viewed as promising vaccine discovery tools and vaccine delivery vectors, and it is worth even considering the possibility of replacing the delivery systems of known vaccines currently in use with phage particles as vaccine carriers. The chapter outlines the current advances in phage vaccine development and analyses possible advances of phages as engineered immunogens.