This article draws on work done in educational psychology to propose a new approach to generating a psychometrically-based measure of second language learnersÆ strategic learning, operationalized as their self-regulatory capacity, as an alternative to the scales traditionally used to quantify language learning strategy use. The self-regulation instrument was developed through a three-phase process, focusing on the realm of vocabulary learning. The first phase involved the generation of an item pool, the second a pilot study in a sizeable sample, and the third an evaluation of the psychometric properties of the revised instrument, using confirmatory and exploratory factor analysis. The results show that the proposed instrument has satisfactory psychometric characteristics and that the hypothesized theoretical model had a good fit with the data. We argue that the results provide evidence for the validity of transferring the theoretical construct of self-regulation from educational psychology to the area of second language acquisition. We also propose that instruments targeting learner self-regulation in a similar way to the questionnaire presented in this study can provide a more psychometrically sound measure of strategic learning than traditional language learning strategy scales.