Abstract Researchers investigating TBLT have used psycholinguistic and sociolinguistic theories in support of the approach, but there has been limited discussion of motivational frameworks. A framework for motivation within TBLT would enhance our understanding of learner motivation, and could be utilised in future studies. This paper argues that Self-Determination Theory is an appropriate framework. After briefly describing the key tenets of TBLT and SDT, the paper shows how SDT helps us understand the motivational benefits of tasks. It outlines the six mini-theories of SDT, and aligns them with existing studies to highlight how results may be explained by these theories. Some suggestions are then provided as to how these theories can be used for conducting future classroom-based research.