Intricate cellular and molecular events occur during plant–pathogen interactions. They cause major metabolic perturbations in the host and alterations in sugar metabolism play a pivotal role in governing the outcome of various kinds of plant–pathogen interactions. Sugar metabolizing enzymes and transporters of both host and pathogen origin get differentially regulated during the interactions. Both plant and pathogen compete for utilizing the host sugar metabolic machinery and in turn promote resistant or susceptible responses. However, the kind of sugar metabolism alteration that is beneficial for the host or pathogen is yet to be properly understood. Recently developed tools and methodologies are facilitating research to understand the intricate dynamics of sugar metabolism during the interactions. The present review elaborates current understanding, future challenges and ongoing quest on sugar metabolism, mobilization and regulation during various plant–pathogen interactions.