The cognitive skills critical for success have largely been studied in Western populations, despite the fact that children in low- and middle-income countries are at risk to not reach their full developmental potential. Moreover, scientists should leverage recent discovery to explore means of boosting cognition in at-risk populations. This semi-randomized controlled trial examined normative cognitive development and whether it could be enhanced by consumption of a probiotic food in a sample of 251 4- to 7-year-old children in urban schools in Côte d'Ivoire. Participants completed executive functioning measures at baseline (T1) and 5 months later (T2). After T1, children in one school received a probiotic (N = 74) or placebo (N = 79) fermented dairy food every day they were in school for one semester; children in the other school (N = 98) continued their diet as usual. Children improved on all tests across time (Cohen's d = 0.08-0.30). The effects of probiotic ingestion were inconclusive and are interpreted with caution due to socio-political factors affecting daily administration. Given the general feasibility of the study, we hope that it will serve as an inspiration for future research into child development and sustainable (health-promoting) interventions for school children in developing nations.