In this study, we examined the relationship between participating in FP and international co-authorship patterns by using a gravity model with proximity dimensions. Our estimates generally confirm the literature about the effect of various proximity types on scientific collaboration. We found that spatial proximity still matters for the cooperation between scientists, considering the progress in communication and transportation. Cognitive proximity appeared as the most influential factor in generating knowledge. Institutional proximity, represented by the similarity of language and being sibling countries, also affects the co-authorship tendencies. Nevertheless, our estimates on the impact of working together in FP projects on co-publication are not as expected. The results show a relationship between co-partnering in FP projects and co-publication behaviours. Yet, the effect is ambiguous and small. These results imply that further research is needed for the effect of international research programs on co-publishing. In addition to different proximity measures, we need meso- (such as regions) and micro-level (such as universities) analyses. Using InCites, which is based on Web of Science (WoS) data, is one of the limitations of our study since WoS coverage favours some research fields and languages. Also, we used aggregated data in this study, while scientific disciplines vary publication and collaboration behaviours. Further research is needed to deal with these limitations.