Background: Sudden Unexpected Infant Deaths (SUID) can occur between 1 month and 1 year of age and are inequitably distributed with a greater burden in populations with numerous health disparities. Modifying the infant sleep environment to promote safe sleep is the most effective risk reduction strategy to reduce SUID. The provision of baby boxes with a mattress and infant supplies has been part of a larger anti-poverty social justice maternity package for decades in Finland. While infant mortality rates have generally improved after the maternity package was introduced, little is known about whether the provision of the baby box increased safe sleep practices. The purpose of the study was to evaluate whether the provision of a Finnish-style baby box reinforced safe infant sleep practice in the home in a low-resource community in Ecuador. Methods: In this longitudinal randomized controlled trial all participants received the same safe sleep education in their third trimester of pregnancy (n = 100). This was followed by randomization into two groups; the control received a diaper bag and newborn gifts, and the intervention group received a baby box and the same gifts at each timepoint. Four infant sleep practices (room sharing, bed sharing/co-sleeping, position, and soft items in the sleep environment) were assessed at 1 month and 1 months post-delivery during a home visit where safe sleep education was also reinforced with both groups. Results: Those in the baby box group were 2.5 times more likely to report safe sleep practices compared with mothers in the diaper bag group at 1 month (odds ratio [OR] = 2.45 and 95% confidence interval [CI]: 1.03–5.86; χ2 = 4.1, p =.043). The group difference was also present at 6-months post-birth: those in the baby box group were 2.9 times more likely to report safe sleep practices compared with those in the diaper bag group (OR = 2.86 and 95% CI: 1.16–7.05; χ2 = 5.2, p =.022). Conclusions: While not all participants used the box regularly, the mothers who received the box were more likely to practice safe sleep at 1 month and 6 months. This suggests the baby box may have served as an important prompt towards safer infant sleep practice. Trial registration: (Clinical Trial Registry, per clinicaltrials.gov: not applicable under 42 CFR 11.22(b) as the study Facility Location was not in the United States (took place in Ecuador), does not involve FDA IND or IDE, and does not involve a drug, biological or device product that is manufactured in and exported from the US for study in another country. The University of San Francisco Quito, Research Ethics Committee in Human Beings approved the study, #2017- 127 M. The University of Kentucky Office of Research Integrity also approved the study, IRB # 42965).