We are pleased to invite you to attend the 39th Meeting of the International Group for the Psychology of Mathematics Education (PME39) to be held in Hobart, Tasmania, Australia from July 13 to July 18, 2015. Mathematics Education: Climbing Mountains, Building Bridges has been chosen as the theme of the conference. This theme provides opportunities to highlight and examine research that considers the challenges, obstacles, links, and connections in mathematics education, with a view to progressing what is known and valuable in the area. The theme Mathematics Education: Climbing Mountains, Building Bridges reflects two of the notable features of the landscape of Hobart: Mount Wellington (or kunanyi, to give it its Aboriginal name), which provides a striking backdrop to the city, and the Tasman Bridge, which crosses the wide Derwent River estuary.