Mothers are fundamental caregivers for under-five children and thus, family participation in child health services is very important. Therefore, a quasi-experimental study for promoting key family practices of mothers with under-five children was conducted among 278 respondents from Oaktwin Cantonment and Inndaing Cantonment in 2014. Data were collected by face-to-face interview with pretested structured questionnaire. Health promotion program including health education and advocacy for unit supports was implemented in study group. Before intervention, baseline data of respondents and pre-intervention knowledge and practices levels were identified. In the three-month and six-month after interventions, post-intervention data collection was done in both groups and data were analyzed. Findings show that there was a statistically significant difference of knowledge and practice scores between study group and control group after three-month interventions (t=10.827, p<0.0001, eta squared=0.297 and t=8.2, p<0.0001, eta squared=0.195, respectively), and six-month post-intervention (t=10.035, p<0.0001, eta squared=0.267 and t=8.773, p<0.0001, eta squared=0.304, respectively). Moreover, knowledge and practice level within study groups have a significant effect for time (F=160.45, p<0.0001 and F=113.06, p<0.0001, respectively) and the magnitude of this effect was also large (eta squared=0.699 for knowledge and 0.621 for practice). At the same time, knowledge and practice of control group have a significant effect for time (F=3.648, p=0.029 and F=19.564, p<0.0001, respectively) but this effect was very small. It can be asserted that health promotion program can improve the knowledge and practice of mothers regarding key family practices. The findings of current study might be a cornerstone for improvement of maternal knowledge and practice on caring for children in the military community.
