Many language teachers at Lac Hong University (LHU) were facing with the inactiveness of the students intheir English classes. Discovering an appropriate way to stimulate their language learning and teaching is a critical question.An examination was carried out in some classes of non-English majors learnt with a variety of games at LHU. After theexamination, most of students showed the wish to learn in a relaxing learning atmosphere with games. During teaching, thewriter detected the benefits of using jigsaw-guessing vocabulary games in her teaching at LHU. Therefore, a research wasconducted on two classes of second-year non-English majors using jigsaw-guessing vocabulary games to find out theeffectiveness of the games as well as the students’ vocabulary retention. An action research with tests, questionnaires, andinterviews was quantitatively and qualitatively used to help find the results. The outcomes of the study displayed that thejigsaw-guessing vocabulary games could improve students’ vocabulary retention and revision and involve the students intheir studying with a relaxing classroom atmosphere (88.2%). 72.7% of her students were interested in their learning ofEnglish. It is believed that the implementation of games in general and jigsaw-guessing game in particular can assist thewriter as well as other language teachers teaching English vocabulary for non-majors at LHU.