Background: The foundations for the growth and optimal development of every human being are laid in the first 2 years of life. Exclusive breastfeeding (EBF) up to 6 months of age and the introduction of complementary feeding (CF) from this age are considered the preventive interventions with the most significant impact on a child’s life. The objective of this study was to determine if pediatricians base their recommendations by following the Guidelines for CF in Healthy Infants (GCFHI) and if mothers have any awareness and knowledge of these recommendations. Methods: Surveys based on the GCFHI were conducted in a group of mothers (n = 377) and pediatricians (n = 104) living in Mexico. Results: Not all pediatricians recommended the EBF, and 76% recommended infant formula before 6 months of age. Regarding mothers, 76.9% practiced the EBF for the first 6 months. Vegetables were the leading starting food of CF suggested by pediatricians and mothers (87% and 91%, respectively), contrasting with food sources of iron (44%), which are the foods of choice according to the GCFHI. The practices performed by the mothers were statistically different from the recommendations of the pediatricians. Conclusions: The results reflect a lack of updating regarding CF. It is imperative to reinforce efforts to maintain the EBF for 6 months and to continue it together with the CF, as well as to promote the beginning of CF based on macro- and micro-nutrients.