This study investigated how task involvement should be practiced to fulfill the theoretical assumptions of Task-Based Instruction (TBI). As the task involvement is to be understood as an indispensable component of TBI, how a high degree of task involvement can be secured and exerted in a most effective way was examined. Having analyzed the data obtained from questionnaire, interviews, reflection papers and proficiency tests, the study indicated that customized and timely feedback and comments on the learners’ performances as well as learners’ sense of responsibility were critical if the task involvement leads to desirable learning outcomes. The study also showed that consciousness-raising (CR) task originated from an authentic task was effective enough to help learners acquire linguistic knowledge in a contextual situation. It made suggestions for how to promote task involvement to better implement TBI, through which the learners can improve language proficiency fully taking advantage of their educational and cognitive experiences.