Introduction: This study was aimed to determine the relationship of variables of psycho-social behaviors in mothers with healthy nutritional eating behavior in primary school students of district 5 in Tehran. Materials and Methods: For this a cross- sectional study, samples were selected by the cluster sampling approach. In total, 200 students were selected from non-government schools in district 5 of Tehran. Data were collected using standardized questionnaires, including the Youth/Adolescent Questionnaire (YAQ), the food frequency questionnaire, the socio-demographic questionnaire, and the Health Action Process Approach questionnaire. Data was analyzed using LISREL 8.8. Results: In the motivational phase, risk perception (P<0.05, β=-0.40), outcome expectation (P<0.05, β=0.34) and task self-efficacy (P<0.05, β=0.23) were significantly associated with nutritional intention behavior. Moreover, action planning was significantly associated with coping planning (P<0.001, β=0.27), two factors accounting for 59% of variance coping planning for diagnostic validation. In the voluntary phase, action planning (P<0.001, β=0.32), coping planning (P<0.001, β=0.27) and proactive improvement (P<0.001, β=0.31) were positively related to healthy nutritional behavior, which explained 79% of the variance. Conclusion: A strong correlation between psychological - social behavior variables in healthy nutritional behaviors of mothers and students’ showed that mothers play a vital role in promoting children's nutritional behaviors. Students training programs should involve mothers in all educational nutrition interventions.