Until recently, it has been argued in economic theory that regional integration and trade agreements among developing countries may achieve negative growth effects. This study tests empirically the effects of such South–South agreements on growth and convergence. All three world regions in question are considered: South America, Southeast Asia, and Sub-Saharan Africa. A comprehensive panel data analysis is conducted that distinguishes between the problems of testing for stronger growth and accelerated convergence, respectively. The data indicate that the considered South–South agreements promote both.