We measure technical efficiency of Peruvian and Chilean port terminals, to evaluate the influence of certain contextual variables in the terminals’ efficiency levels. The sample includes 14 port terminals from 2004 to 2014. Due to the potential differences, we have estimated a DEA model in a non-convex metafrontier framework. Afterwards, we estimated all the regression models proposed in the literature that could be used to explain not only the technical efficiency estimated with respect to the metafrontier (TE*) but also each one of its components: the technical efficiency with respect to the group-specific frontier (TEk) and the technological gap ratio (TGR). Results are robust across models.