The academic literature on the foreign policy behaviour of coalition governments has in common that it compares the foreign policies of coalition governments to that of single-party governments. However, as for instance Kaarbo and Beasley (2008) note, there is no differentiation between different types or configurations of coalition governments. The working hypotheses of this paper are that (a) the causal mechanisms identified by the literature on the foreign policies of coalitions should work out differently in different kinds of coalition and (b) differences in organisation/structure of foreign policy decision making in coalitions should lead to different effects of coalition government on foreign policy. The paper tests these hypotheses in case studies on the foreign policies of the recent coalition governments in Germany and the United Kingdom.