Alpha-enolase (ENO1) is a metabolic enzyme involved in the synthesis of pyruvate. It also acts as a plasminogen receptor and mediates the activation of plasmin and extracellular matrix degradation. In tumor cells, ENO1 is up-regulated and supports the Warburg effect; it is expressed at the cell surface, where it promotes cancer invasion, and is subjected to a specific array of post-translational modifications, namely acetylation, methylation and phosphorylation. ENO1 overexpression and post-translational modifications could be of diagnostic and prognostic value in many cancer types. Information on the biochemical, proteomics and immunological characterization of ENO1, and particularly its ability to trigger a strong specific humoral and cellular immune response, make this ubiquitous protein an interesting tumor target; DNA vaccination with ENO1 in preclinical models efficiently delays the development of very aggressive tumors such as pancreatic cancer. This review aims to analyze the main stages by which the tumor associated antigen (TAA) ENO1 has become a promising target that opens potential avenues for cancer immunotherapy.