Background: An infant’s requirement for daily energy and nutrients appears to exceed what breast-feeding gives; consequently, incorporating complementary foods into the diet becomes vital for the growth and development of the infant. The study aims to explore the correlation between the age of complementary feeding introduction before the sixth month and its impact on hemoglobin levels and weight status. Subjects and Method: We conducted a case-series study at the Primary Health Care Center/Al-Tahrir, Baquba City, from April 18 to August 30, 2018. The study included a sample of three hundred fully developed infants, aged between 6 and 12 months, consisting of 180 males and 120 females. The dependent variable was complementary feeding. The independent variables were weight status, haemoglobin levels, and weught for age z-score. We obtained the data through face-to-face interviews with the child's mother using a structured questionnaire. Results: Among the women who took part in the study, 43% initiated the practice of providing additional food to their infants between the ages of 4 and 6 months. It was observed that the average hemoglobin level was higher in infants who consumed complementary feeding during the period of 4–6 months. A significant percentage of infants (52.6%) who initiated food intake by nursing or bottle feeding between the ages of 4-6 months exhibited weight levels within the normal range. In contrast, infants who had not yet commenced supplemental feeding showed a lower prevalence of normal weight levels. Furthermore, a majority of infants (83.3%) who engaged in supplemental feeding experienced an increase in hemoglobin levels and an improvement in weight. The research findings indicate that the introduction of supplemental nutrition throughout the period of 4 to 6 months of age has a significant impact on enhancing hemoglobin levels and weight among infants. Conclusion: The study's findings show that mothers frequently reported offering rice water, biscuits, and tea-soaked bread as their primary food sources.