The purpose of this paper is to (a) establish whether meaning recall and meaning recognition item formats test psychometrically distinct constructs of vocabulary knowledge which measure separate skills, and, if so, (b) determine whether each construct possesses unique properties predictive of L2 reading proficiency. Factor analyses and hierarchical regression were conducted on results derived from the two vocabulary item formats in order to test this hypothesis. The results indicated that although the two-factor model had better fit and meaning recall and meaning recognition can be considered distinct psychometrically, discriminant validity between the two factors is questionable. In hierarchical regression models, meaning recognition knowledge did not make a statistically significant contribution to explaining reading proficiency over meaning recall knowledge. However, when the roles were reversed, meaning recall did make a significant contribution to the model beyond the variance explained by meaning recognition alone. The results suggest that meaning recognition does not tap into unique aspects of vocabulary knowledge and provide empirical support for meaning recall as a superior predictor of reading proficiency for research purposes.