The interstitial lung diseases (ILD) are a group of heterogeneous diseases that exert significant morbidity and mortality in connective tissue diseases (CTD). There is no consensus on measures of disease activity or therapeutic responsiveness, which hampers effective drug development and regulatory evaluation of candidate therapies. The CTD-ILD Special Interest Group represents an international multidisciplinary effort to identify consensus on criteria to measure disease activity and therapeutic response in CTD-ILD. We summarize the design of the studies we are conducting and progress leading to the OMERACT 10 and 2010 EULAR meetings.