The present study aimed to examine the effect of three vocabulary techniques (dictionary use, etymological analysis, and glossing) on Iranian ESP learners' vocabulary production. Forty-five university students majoring in architecture at Azad University, Anzali branch, participated in this study. They were divided into three groups, and each group was randomly assigned to one kind of treatment condition (dictionary use group, etymology group, and glossing group). The Michigan proficiency test was used to ensure the homogeneity of the ESP learners. The three experimental groups received instruction for three weeks. ESP learners took a vocabulary production test (VPT). A one-way between groups ANOVA was conducted to analyse the data. The results showed that dictionary use group improved ESP learners' vocabulary production, and dictioary group outperformed the other two groups. The study concludes that dictionary use faciliates vocabulary production
