The relationship between altitude of residence and child linear growth is studied using data for 630,499 children below age 5 years born between 1992 and 2016, as recorded in 47 countries at elevations ranging from − 377 to 4498 m above sea level. Regressions are used to measure the role of household, community, and environmental factors in explaining an observed altitude effect on linear growth. Controlling for birth year and country effects, and a range of factors correlated with altitude and associated with nutrition outcomes, for each 1000 m gain in elevation, height for age z score (HAZ) declines by 0.195 points on average. Country-specific estimates of the association vary and include positive associations. Results highlight the potential links between developmental risks for children and features of their physical environment.