The purpose of this analysis is to present and test an information processing theory of interest group influence in the EU. While it has long been acknowledged that information is the currency of lobbying in the EU, a systematic examination of how interest groups gather, generate, synthesise, and transmit information to decision-makers is still missing. I posit that interest group influence is a function of a group’s ability to efficiently process information. Conceptualising influence in this way not only brings the study of influence in-line with key insights from the larger interest group literature, but it also helps avoid some serious methodological issues related to measuring influence. Using data from a large-scale online survey and elite interviews I compare how information processing varies across six different types of interest groups. The results suggest that most types of interest groups in the EU have similar information processing capabilities and thus, that influence in the EU appears to be, on balance, fair and impartial.