BackgroundAdolescent pregnancy is a multidimensional public health problem. It is known that every year in Brazil approximately 1.1 million adolescents become pregnant and around 20% of all newborns are born to teenage mothers. AimThis ecological study describes the spatio-temporal patterns of the percentages of live births to adolescent mothers between the years of 2010 and 2016 in Brazil and their associations with human development indexes in the meso-regions where they reside. MethodsPercentages of live births to adolescent mothers are the ratio between the number of live births to women aged 10–19 years old and total number of live births in each Brazilian meso-regions during the study period. A spatio-temporal Bayesian model was used to associate the percentages of live births to adolescent mothers with the human development index of each meso-region. Moran’s index was used to measure the spatial autocorrelation between the meso-regions at an aggregate level, whereas the local indicator of spatial auto-correlation measured local correlation. FindingsPercentages of live births to adolescent mothers for the whole country were 19.3% in 2010 and 17.5% in 2016. There is a heterogeneous spatial distribution pattern for these percentages, being the highest percentages in the North region (24.8% in 2016) and the lowest percentages in the Southeast region of the country (14.3% in 2016). The Bayesian model showed that meso-regions with lower human development index values have higher percentages of live births to adolescent mothers. ConclusionOur findings suggest that adolescent pregnancy is deeply associated with environmental characteristics.