Framing plays an important role in politics. Interest groups strategically employ political rhetoric to structure how a policy issue is discussed and to achieve their preferred policy outcome. Despite the central role of political rhetoric, we know remarkably little about framing strategies of interest groups. This paper aims to close this important gap by studying the determinants of framing strategies of interest groups. We hypothesize that framing varies with actor type as the nature of the interest that lobbyists represent constrain their choice of framing strategies. Our theoretical expectations are tested based on a new and innovative dataset on interest group framing. Drawing on a quantitative text analysis of more than 3,000 submissions to legislative consultations, we identify the frames put forward by interest groups in more than 50 policy debates. Using multilevel modeling, we test the effect of actor type on framing strategies while controlling for the characteristics of the policy debate.