The aim of this study is to evaluate and compare mothers' and grandparents' feeding behaviours, the differences between the behaviours, the relationship between children's feeding problems and grandparents' feeding behaviours, as well as the relationship between grandparents' feeding behaviour and children's body mass index (BMI). This study prompts physicians to pay attention to the on feeding behaviours of grandmothers when evaluating the feeding problems and behaviours of children. This study is a controlled case study. Two hundred children (between 2 and 5years of age) were included. Amongst these children, 150 of them were only fed by their mothers and 50 of them were fed by both their mother and grandmother. The feeding behaviour was evaluated by the Comprehensive Feeding Practices Questionnaire (CFPQ).Three domains emerged in this study:Some of the feeding behaviours were significantly different between the mothers and grandmothers who were questioned in the CFPQ.The feeding behaviours are related to the feeding problems; in this study, we show that, in some cases, whether some feeding behaviours were applied either more or less had a significant influence on feeding problems.There were positive correlations between the feeding behaviours of mothers and grandmothers.Conclusion: There is limited research about grandmothers' influence on child feeding. Research in grandmothers' feeding behaviours may reveal key concerns in children feeding problems and in preventing childhood obesity.