The American Academy of Pediatrics recommends, through the implementation of the “Back to Sleep (BTS)” campaign, the supine sleeping position for infant sleeping since it prevents to prevent Sudden Infant Death Syndrome (SIDS). Objective: To describe the sleeping position of a group of infants and the risk factors associated with sudden infant death syndrome (SIDS). Subjects and Method: Prospective pilot study, including infants < 45 days of life in well-child care visits at a medical center. Exclusion criteria: Preterm-born infant (gestational age < 37 weeks) and/or comorbidities (pulmonary, metabolic, cardiologic). A brief parental questionnaire was conducted regarding general demographic data and sleep habits. The questioner was based on the BISQ-Spanish version, due to the lack of validated instruments for infants < 3-month-old. Results: We included a sample of 100 infants between 16.78 ± 12.88 days old (57% girls). Mothers were the main information source (84%). 79% of the infants slept in supine position, 19% slept on their sides, and 2% in prone position. Regarding the place where the infants slept, 66% did in their crib in the parents’ room and 31% slept in parents’ bed. 74% of infants fell asleep while being fed. 28% of infants were exposed to passive smoking at home. 91% of parents were informed about safe sleep positions, reporting that pediatricians were the main source of information (54%). Conclu-sion: We found a high percentage of infants < 45 days of life who slept in an unsafe position, and frequently co-sleep with their parents. Thus, it is important to implement local SIDS prevention campaigns to reinforce safe infant sleep.