BACKGROUND: Maternal and neonatal outcomes have improved substantially. During the same period, the caesarean delivery rate soared. The aim of this analysis was to determine whether an increase in caesarean rate was associated with an improvement in perinatal outcome at an institutional level in low- and middle-income countries. METHODS: The WHO Global Survey on Maternal and Perinatal Health (WHOGS) and the WHO Multi-Country Survey on Maternal and Newborn Health (WHOMCS) were two multi-country, facility-based, cross-sectional surveys conducted in 2004-08 and 2010-11, respectively. The increase in caesarean rate and the change of prevalence of adverse perinatal outcomes were calculated using a two-point estimator of percent change annualized (PCA) method. Maternal, perinatal, and neonatal composite indexes were used as the outcomes. A linear mixed model was used to assess the association between the change of caesarean rate and the change of perinatal outcome. RESULTS: A total of 259 facilities in 20 countries participated in both surveys, with 217 844 women in WHOGS and 227 734 women in WHOMCS. The caesarean rate in these facilities increased, on average, by 4.0% annually, while the prevalence of adverse perinatal outcomes decreased by 4.6% annually. However, after adjustments for potential confounders, no association was found between the increase in caesarean rate and the change of adverse outcome indexes, regardless of whether starting caesarean rates were already high (above 10%) or not. CONCLUSIONS: In low- and middle-income countries, the increases in caesarean rates were not associated with improved perinatal outcomes regardless of whether the starting caesarean rate was already high or not.