The present investigation was an attempt to study the effect of using compensation and determination strategies on Iranian upper-intermediate EFL learners' vocabulary development. The question which the present study was trying to answer was: Do compensation and determination strategies have any statistically significant effects on Iranian upper- intermediate EFL learners' vocabulary development? To that end, QPT was administered to 110 female EFL learners learning English language at Shokouh Institute in Rasht, Iran. So 90 learners were selected for this study and they were divided into two experimental groups and one control group, each group contained 30 learners. Prior to the treatment, the participants were given a pretest to assess their initial knowledge of English vocabulary. The experimental groups received treatment. The researcher used compensation and determination strategies in ten sessions. However, in the control group, the new words were taught in traditional way. After ten sessions, a posttest was administered to all groups. One-way ANOVA was conducted to see if the treatment was effective or not. The results were computed and analyzed through SPSS and it was found that using compensation and determination strategies had a positive effect on the participants' vocabulary development.