Despite the availability of studies on mobile learning adoption, its theoretical foundations have not yet matured. However, studies on mobile learning adoption in the context of form six student in Malaysia is still very limited. Against this concern, a study was conducted with the aim of investigating factors that could influence the adoption of mobile learning. Based on The Unified Theory of Acceptance and Use of Technology (UTAUT) and two other variables which are Perceived Playfulness and Self-Directed Learning, an empirical structured has been developed to identify predictors of mobile learning. A self-administered questionnaire was adopted and a total of 314 responses were employed for the analysis, using Structural Equation Modelling (SEM). The findings of the analysis revealed that all key constructs (except social influence) affect mobile learning adoption among form six students. Besides that, Self-Directed Learning become the strongest predictor and followed by Effort Expectancy. These findings provide crucial implications for educators and practitioners to take individual characteristic (Self-Directed Learning) into consideration while promoting mobile learning. This study represents one of the few attempts to reveal the extended UTAUT model could be increased explanation power of technology acceptance by the users. Directions for future study are suggested at the end of the paper.