This study investigates the claim that task-induced involvement load has an effect on vocabulary learning and examines the effect of task types and word concreteness on intentional vocabulary learning in the Korean EFL context. This study aims at testing whether productive word-focused tasks lead to equally effective vocabulary learning when the total involvement load index is equal but the distribution of index levels of each component (need, search, and evaluation) is different. The three productive word-focused task types are gap-fillig, sentence writing, and gap-filling through word transformation. In addition, in order to investigate the effect of word concreteness on vocabulary learning, two groups of target words were selected based on the level of word concreteness. In sum, the results of this study generally supported involvement load hypothesis (Laufer & Hulstijin, 2001) and test types and proficiency levels proved to be important variables that affect vocabulary learning. Moreover, the findings also indicated that word concreteness was not a major factor in vocabulary learning. The pedagogical implications and further suggestions are discussed.