The cognitive items covering the domain of scientific literacy in the Programme for International Student Assessment (PISA) are explored through an analysis of the item residuals (item-by-country interactions) with the aim of looking for a distinct Nordic pattern. The findings of a cluster analysis indicate that the profile across the Nordic countries is not very distinct. However, stable profiles are established for a number of other groups of countries, and the Nordic countries are shown to be members of a larger group of countries which is labelled North-West European countries. Furthermore, item characteristics are used to find possible explanations for the profiles.