Typically, publications in the social sciences and humanities (SSH) tend to be written more in national languages as opposed to English or other lingua franca. Similarly, the types of publications often are much more diverse. These two are assumptions that can be best studied using national data and, preferably, by means of comparisons of two or more countries. However, cross-country comparisons using national data, as we will show, contain a range of methodological challenges.Interest in SSH publication patterns led to an exploratory study, the preliminary results of which are presented here. The study aimed to acquire a general insight into differences and similarities in publication patterns within SSH across 13 European countries (among them: Denmark, Finland, Norway, and Sweden). The aim was pursued by means of a questionnaire containing questions on national databases in the respective countries and series of bibliometric indicators (e.g., the share of publications in English, the share of co-authored publications).The preliminary findings point to considerable differences in designs of national databases and practices of data registration and processing. Hence, an accurate interpretation of cross-country comparison of indicators is not achievable without an examination of the role that the differences in, say, classifications of publication types, play in the resulting indicators. Such methodological challenges are the focus of the presentation.