Height convergence across Italian regions during the second half of the twentieth century is a widely recognized fact. However, it has been suggested that this process was partly affected by the massive migratory flow of people from southern to northern Italy in the 1950s and 1960s, which greatly slowed the height growth rate in the receiving regions, since immigrants were on average shorter than the receiving northern population. The main aims of this study were to estimate the speed of height convergence of Italian military conscripts in the second half of the twentieth century, and to estimate the contribution of internal migration from the south to the north of Italy to height convergence. We hypothesized that migrants from southern Italy reduced height levels among northerners relative to what they would have been without considering migration. We used cohort data on Italian conscripts born in 1951 and 1980. Results indicate that internal migration may explain from 24 to 32.7 percent of height convergence, meaning that ignoring migration flows yields an overestimation of the height changes for conscripts living in the south of Italy.