Background: Although exclusive breastfeeding is recommended in the first hours of life, it is common to offer infant formula to the newborn, resulting in a negative effect on breastfeeding. This study has the objective of identifying the prevalence of the offer of food complements, its characteristics and the determining factors. Methods: Cross-sectional study, linked to a cohort study that assessed the newborn care in four public maternity wards in Natal. The sample was composed of 415 mothers and full-term newborns, with appropriate weight for gestational age and Apgar scores in 1st and 5th minutes ≥ 7. In order to analyze the association between the socioeconomic, biological and welfare characteristics and the offer of the complement for the newborn, we used Pearson’s Chi-Square, Student’s t-test, and Poisson’s regression.Results: Of the 415 newborns, 51.3% received complements (57.6% in the first hour of life), of which 92% with infant formula. Of these, only 50.7% were prescribed by the doctor. Colostrum deficiency was the main reason for indication (33.8%). The maternal age ≤ 20 years (PR=0.64; 95% CI=0.47-0.86) and between 20-30 years (PR=0.70; 95% CI=0.57-0.87) were shown as protective factors, while being primiparous (PR=1.37; 95% CI=1.11-1.60) and had undergone cesarean section (PR=1.2; 95% CI=1.00-1.45) as predictive factors. Conclusion: We observed that maternal characteristics are determinants for the offer of complement to the newborn in the first hours of life. The high prevalence shows the need for interventions that minimize the inadequate offer of infant formula and promote exclusive breastfeeding before hospital discharge.