Over the past decade, research involving immunometabolism, has been gaining much interest. The immune cell re-sponses of an individual may be influenced by metabolites released by the host or derived from the microbiota. How-ever, the immune response of an individual may vary depending on the health condition of an individual. During infection, the metabolic processes derived from the infectious diseases can effect the function of immune cells and thus determine the response or survival of the host during infection. Immunometabolism also has a role in tumor development although the mechanism of how tumor cells influence immune cell function is not well understood. Among the major meatbolic pathways that have been studied in immune cells include glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway, fatty acid oxidation, fatty acid synthesis and amino acid metabolism. Understanding the tight connection between metabolomics and immunity in health and disease will be crucial as this could lead to therapeutic interventions or in developing metabolomic biomarkers in immunology.