Intercultural studies induced many controversies in the characteristics associated with sleep problems. Objectives. – The aim of this study was three fold: (1) to compare sleep problem frequency in two culturally different populations; (2) to analyze if some particular bedtime routines (“ co-sleeping”, “distal” or “proximal” parent–infant interaction) are associated to trouble; (3) to show influence of the cultural context to trouble. Population. – This study examines bedtime routines in French infants aged 12 to 24 months in maternal and infant’s protect center (PMI) in Lyon and la Réunion island, for a sleep — cross cultural approach. Three hundred infants were enrolled in the survey. Results. – We showed prominent sleep problems in la Réunion’s group (35%) in comparison with the group in Lyon (17%) ( P <0.005). Regression analysis allowed to draw relations between several factors and the sleep problems. Hence, proximal bedtime routines and interactions (CR =0.530, P =0.05), “co-sleeping” (CR =0.989, P =0.005) and parental presence at bedtime until infant falls asleep (CR =0.595, P =0.04) are significantly associated with sleep problems. These attitudes are more frequent in la Réunion’s group. Conclusion. – Our study confirms literature data and asks question about cultural meaning for these inadequate behaviors in relation to mother–infant separation distress. Acculturation notion is called forth in la Réunion’s group.