Abstract This study investigated the effects of vocabulary games on primary school students‟ English vocabulary learning particularly examining their effects on vocabulary learning motivation, peer-interaction, and achievement. Guided by the Socio-cultural Theory and the Social Constructivist Model, an experiment was conducted to see the differences in students‟ vocabulary learning with and without games between randomly selected experimental (N=49) and control (N=48) groups. The experimental group learned vocabulary lessons through four games; namely: Memory Game, Outburst, Chain Game, and At the Zoo whereas the control group followed the conventional methods. A pretest posttest comparison group quasi-experimental design and a convergent parallel design type of mixed methods design were employed. The participants of the study were grade six students at Atse Sertse Dingil Primary School, Bahir Dar. For data collection purposes, tests, questionnaires, interviews, and observations were used. While quantitative data were computed using One-way MANOVA after several assumptions were checked qualitative data were analyzed descriptively and thematically. The findings of the study showed that after the intervention the experimental group significantly excelled the control group in overall vocabulary learning (Wilks‟ λ = 0.840, p<0.05). Nevertheless, with respect to the univariate tests, this comparison was found to be significant on vocabulary learning motivation (p<0.05) and achievement (p<0.05) while peer-interaction remained non-significant (p<0.05). The qualitative evidence associated with these variations was also explained. Based on the findings, it was concluded that vocabulary games are worth-considering for teaching English vocabulary to students in the primary school, especially to improve learners‟ vocabulary learning motivation and achievement. Key words: Vocabulary games, motivation, peer-interaction, achievement, Bahir Dar