Abstract: Container ports are leading actors in globalisation. They serve massed (increasingly larger ships) and planetary (organised in networks) logistics processes. There is evidence of a high relationship between containerised cargo and ports' performance. However, there is also a lack of literature regarding its sources. This paper uses frontier analysis techniques to investigate whether the type of activity (import/export, transhipment or cabotage) is crucial in explaining port efficiency. To this end, a two-stage procedure is proposed. In the first stage, the efficiency of ten Spanish ports specialised in container traffic is estimated by DEA techniques. In the second, the different types of container traffic activities are evaluated. Results suggested that port efficiency is: 1) highly related to the typology of containerisation activity; 2) through a non-linear form (inverted U-shape). Thus, ports that combine both transhipment and import-export activities outperform those specialised in one of these activities