<p>This article contributes to the literature on the biological standard of living, revisiting how the height catch-up process that occurred in Italy during the mid-twentieth century was affected by regional and subregional patterns of economic growth and environmental conditions, at an unprecedented geographical level of precision. To do so, we use an unexplored micro-dataset drawn from the 1951 and 1980 birth cohorts of military conscripts in Italy. We propose a multistep estimation strategy to isolate the height catch-up process from factors specifically regarding the convergence in the South. The rich information available in our dataset concerning the place of birth and residence of conscripts allows us to disentangle the contribution of internal migration from other convergence factors during the 1950s and 1960s, where public investments and subsidies had a preeminent role. The findings suggest that the height convergence of the South was mainly strengthened by public intervention, which improved the standard of living within this macro-area, while it was less connected to internal migration from the South to the North.</p>