The purpose of the study was to compare the effectiveness of hierarchy vocabulary exercises and copying vocabulary exercises on EFL students’ vocabulary acquisition and reading comprehension. Two specific factors were probed: (a) vocabulary gains and retention from different exercises; (b) reading comprehension performance through different exercises. Fifty-six Grade 5 students in Yanpu Elementary School in Taiwan were engaged in either hierarchy vocabulary exercises or copying vocabulary exercises, with sixteen target words. The results revealed that the experimental group receiving hierarchy vocabulary exercises significantly outperformed the control group receiving copying vocabulary exercises on students’ performance of vocabulary gains, reading comprehension, as well as short-term and long-term word memory retention. A positive correlation between vocabulary knowledge and reading comprehension was also inspected. It was, therefore, concluded that hierarchy vocabulary exercise was a more effective exercise type for vocabulary acquisition and reading comprehension.