This article reports on a strategy training study that investigated the lexical processing strategies (LPSs; ignore, consult, infer) used by L2 learners when they encounter unfamiliar vocabulary while reading and the impact of these strategies on vocabulary learning. A time-series with repeated-measures design was used. Introspective data were gathered from eight participants (Francophone university students, intermediate ESL proficiency) on eight texts over 5 months to elicit LPS use on self-identified unfamiliar words. Then, 1 week after each reading, participants completed a cued recall task to measure their learning of these words. An analysis of overall LPS use (changes in patterns and effectiveness of strategy use with LPS-focused instruction) and word retention rates demonstrates the potential for vocabulary learning through reading and indicates that some LPSs lead to higher retention rates than others. This research increases our understanding of the role of LPS use in vocabulary learning and suggests some reevaluation of current pedagogic practice.