This article investigates empirically the nature and the dynamics of intra-regional trade in North America. Specifically, we analyze intra-NAFTA patterns of horizontal and vertical intra-industry trade - H(V)IIT - in the United States, Canada and Mexico over the 1992-2002 period and examine some industry characteristics of observed IIT patterns for each IIT component. The results indicate that though HIIT and VIIT exhibit different trends, both IIT types are important in labour/resource-intensive sectors, suggesting that comparative advantage may be an important factor in intra-NAFTA IIT. The most striking finding is that HIIT is consistently increasing, while VIIT exhibits a significant downward trend. Hence, our findings suggest that intra-NAFTA IIT has increasingly become an exchange of different varieties rather than different qualities, indicating to some extent an economic convergence process within the NAFTA trade bloc.