Increasingly, scientific and technical collaborations are viewed as legitimate components of diplomatic expression by many countries. In the U.S., the Department of State has recently designated “science envoys” to Muslim nations to arrange scientific collaborations between the United States and countries in North Africa, the Middle East, and South and Southeast Asia. These envoys are concerned primarily with the policy of international scientific and technical cooperation. The inclusion of science in the nation’s diplomatic activities constitutes an element of soft power, which uses civilian instruments to increase national security (economic aid, strategic communications, and information sharing) and to win the hearts and minds of people around the world. While involvement in the policy of science diplomacy is beyond the scope of most scientists, the practice of science diplomacy can include scientists whose work and research takes them overseas and that involves collaboration with foreign scientists. This symposium focuses on the practice of science diplomacy in the earth sciences. Speakers will describe several case studies of successful international science program activities and see how those activities have contributed to improved international cooperation and interaction. The panel will examine key lessons learned during these successful scientific activities and draw a suggested set of best practices for those wishing to engage in the practice of science diplomacy.