The Second IUPAC–ACS Collaboration Summit was convened on 21 March 2010 during the American Chemical Society (ACS) meeting in San Francisco, California, USA, under the auspices of IUPAC, ACS, and the U.S. National Academies (through its role as the U.S. adhering member to IUPAC). The meeting—attended by approximately 40 representatives of IUPAC and ACS technical divisions and committees—built on the success of an inaugural collaboration event held on 15 August 2009 in Washington, D.C. While the previous summit focused on developing broad awareness of the activities and interests of participating IUPAC and ACS groups, the second summit focused on generating concrete collaborative ideas to be taken forward by these groups.