One hundred and fifty years ago, a meteorological conference was held in Leipzig as part of the anniversary meeting of the Society of German Natural Scientists and Physicians (Gesellschaft Deutscher Naturforscher und Ärzte), founded in Leipzig in 1822. This meeting, intended as a preparatory meeting for the 1st International Meteorological Congress held in Vienna a year later, ultimately laid the foundation for today's World Meteorological Organization. The organizers of the Leipzig Conference (was held on 14–16 August 1872) were the German Carl Christians Bruhns (1830–1881), the Austrian Carl Jelinek (1822–1876) and the Swiss Heinrich von Wild (1833–1902). The discussions at the conference were conducted on the basis of a catalogue of 26 questions on the most pressing issues of the use of measuring instruments, observation periods, and data exchange (catalog in English translation in the appendix) that were sent together with the invitation. The main concern here was to enable consistency between individual states. Based on the Report on the Negotiations of the Meteorological Assembly at Leipzig (Vienna, 1872), which also contains opinions expressed by meteorologists who were not present at the conference, the results of this trend-setting Leipzig assembly are presented here, that was a milestone in international meteorological cooperation.