Studies on transfer of training generally focus on training input factors such as trainee characteristics, training design and work environment. The Learning Transfer System Inventory (LTSI) conceptual model developed by Holton, Bates & Ruona (2000) is a more comprehensive model that accounts for the impact of primary intervening variables such as motivation, environment, ability and secondary influence factors such as performance self-efficacy and learner readiness. Nevertheless this model does not consider the influence of knowledge sharing on transfer of training. We argue that knowledge sharing could play a key role in understanding transfer of training. We base this hypothesis on the principles of the theory of planned behaviour (TPB), which predicts trainees' behavioural intentions and actual behaviour of sharing the learned knowledge, skills and attitudes in the workplace. Consequently, this paper proposes a research strategy to test the importance of knowledge sharing as a factor in predicting transfer of training by combining the LTSI and TPB.