This study investigated the effect of an informal values education programme on the development of concept of responsibilities among 5^th grade students from ethnic minority groups in Vietnam. For this purpose, 38 students from an experimental group received a values education intervention, while 38 students from a control group did not. The intervention programme was adapted into the Vietnam culture in general and into the Vietnam ethnic minority groups' characteristics in particular. The pre-test and post-test of both groups were evaluated using a questionnaire that measured children's concept of responsibilities designed for the purposes of the study. Findings showed significant differences between the pre-test and post-test for the experimental group on the specified variables but not for the control group. Based on the results, an informal values education programme that has been culturally adapted is therefore suggested to make a positive impact on the development of concept of responsibilities among 5^th grade students from the ethnic minority groups in Vietnam.