In this article, we compared French and Cameroonian schoolchildren's initial conceptions and comprehension of the night and day cycle in order to test for cultural influence. Forty students aged almost 8 years (Grade 2) were individually interviewed in their schools about night and day dynamics before they had received any teaching in astronomy. Results indicated that French children have significantly more heliocentric knowledge about the night and day cycle than Cameroonian children who propose rather a geocentric view, underlining the impact of cultural mediation (e.g., artifacts, media, and personal accounts). French children, who grow up in a mechanistic culture, give explanations of the night and day cycle based on the Earth's rotation, whereas their Cameroonian peers, who live in an animistic society, mainly propose movements of the Sun to explain the cycle (consistent with their observations and local cosmologies). Regarding the organization of this knowledge, we found that only a few children had a coherent model of the night and day cycle. It did not appear to be influenced by cultural context, as both the French and Cameroonian children's conceptions were mainly fragmented.