Introduction: Since vocabulary is a key basis on which reading achievement depends, various vocabulary acquisition techniques have become pivotal. Among the many teaching approaches, traditional or otherwise, the use of crossword puzzles seems to offer potential and a solution for the problem of learning vocabulary. Method: This study was conducted to examine the effects of crossword puzzles on vocabulary acquisition of first-year students. Sixty-eight students enrolled in a fundamental English course participated in the study. The instruments were pre-and post-vocabulary tests and a questionnaire surveying the students' attitudes toward learning. Results: The findings revealed that the students' overall post-test score was higher than their pre-test score at a significance level of 0.05. When classifying students into three groups based on their vocabulary proficiency, it was found that students in all groups could improve their vocabulary knowledge at a significance level of 0.05. The results from Repeated Measures Analysis of Variance test showed that significant differences existed in the scores of the three tests which students gained from the tests and the final exam. The results of the questionnaire also illustrated their very favorable attitudes toward learning vocabulary through crosswords as a whole. Discussion and Conclusion: Crossword puzzles can help students improve vocabulary knowledge, meanwhile increase their learning motivation.