Vocabulary notebooks are frequently advocated as a way for students to take control of their vocabulary learning (Fowle, 2002), with the added benefit of improvements in vocabulary learning (Schmitt and Schmitt, 1995; Laufer and Nation, 1999). The study described in this article attempts to lend empirical support to these claims, by investigating the effect of vocabulary notebooks on EFL students' vocabulary acquisition. Students in three lower intermediate EFL classes participated in the study. A vocabulary notebook program was implemented in one class over a 4-week period, with the remaining two classes acting as control groups, following the same curriculum with the same materials but without keeping vocabulary notebooks. Receptive and controlled productive vocabulary tests revealed significantly greater learning of the target words in the treatment group. In addition, students in the treatment group demonstrated a greater tendency to use the target words in free writing compositions. However, a positive impact on learner autonomy--as has been reported in previous studies (McCarthy, 1990)--was not observed. These findings lead the authors to conclude that vocabulary notebooks can be an effective learning tool in EFL classrooms, but positive impacts on learner autonomy may not be seen in the absence of appropriate motivation for language learning. (Contains 5 tables and 1 note.)