In the wake of a severe economic crisis in the 1980s Costa Rica abandoned animport substitution model of development adopted in the 1960s andimplemented policies supporting foreign investment and the diversificationof its exports. This study presents an application of the model proposed byHerzer and Nowak-Lehnmann to test the hypothesis that export diversificationhas contributed to economic growth in Costa Rica via externalities oflearning-by-doing and learning-by-exporting over the period of 1965–2006.After using the autoregressive distributed lags and dynamic ordinary leastsquares models no long-run relationship was found between exportdiversification and growth.