OBJECTIVE: To analyze the association between grand multiparity and maternal and neonatal morbidity and mortality. DESIGN: Retrospective cross-sectional study. SETTING: Point G National Hospital, a tertiary care hospital in Bamako, Mali. POPULATION: All singleton births from 1985 to 2003. METHODS: Cross-sectional study of 13 340 singleton births at a tertiary care hospital in Mali (1985-2003) compared outcomes between 3617 grand multiparas (para ≥5) and 9723 pauciparas (para 1-4). Odds ratios (OR) were adjusted for maternal age, prenatal care utilization, socioeconomic status, and region of origin. MAIN OUTCOME MEASURES: Maternal mortality, perinatal mortality, placental abnormalities (previa and abruption), uterine rupture, postpartum infection, postpartum hemorrhage, eclampsia, cesarean delivery, mean birthweight, low birthweight, high birthweight. RESULTS: Grand multiparas were older, poorer, and less likely to have accessed prenatal care. Grand multiparas had a lower adjusted odds of maternal death (adjusted OR, 0.66; 95%CI, 0.45-0.97), but higher adjusted odds of perinatal death (adjusted OR, 1.33; 95%CI, 1.12-1.59), placental abnormalities (adjusted OR, 1.57; 95%CI, 1.21-2.05), and high birthweight (adjusted OR, 1.42; 95%CI, 1.05-1.92). CONCLUSIONS: The healthy person effect may explain grand multiparas' lower odds of maternal death. Reducing grand multiparity and improving grand multiparas' access to prenatal care may improve population-level perinatal outcomes.