Background: In the first three years of life, good nutrition plays an important role in forming a good foundation that has impact on child’s future physical and mental development. In this study we are focussing on the nutritional and immunization status in children 6months to 3 years attending immunization clinic,UHTC,IGIMS,PATNA with special emphasis to identify moderate acute malnutrition (MAM) and severe acute malnutrition (SAM) cases. Methods : It is an observational study carried out immunization clinic at UHTC,I.G.I.M.S. Patna included 400 cases age between 6 months to 3 years This study was conducted from January 2019 to June 2019 in immunization clinic UHTC, IGIMS Patna. Results: Incidence of SAM and MAM is 7.5% and 30.75 % respectively. Female predominance was seen in SAM and MAM i.e. 53.4% and 54.6% respectively. Significant association of under–nutrition was found with LBW (p<0.05), not giving exclusive breast feeding up to 6 months of life (p<0.05) and, Low socioeconomic status (p<0.001). Higher numbers of females were unvaccinated. Conclusions: Despite our great effort for improving maternal and child health, significant number of children are malnourished and unimmunized. So, for their better health we need to start from birth, institutional delivery, exclusive breast feeding, immunization, and timely introduction of complementary feeds, marriages at appropriate age, proper antenatal visits and birth spacing.