A Lunar Petrology Conference, sponsored by the Lunar Science Institute under NASA contract NSR‐09‐051‐001 and attended by nearly 100 scientists, was held from July 24 to 26, 1973, in Houston, Texas.The principal aim of the conference was to bring together penologists and geochemists active in lunar research to discuss the present status of lunar petrology. The emphasis was placed on discussion with a minimum of formal presentations. In each session two or three keynote speakers reviewed present knowledge and highlighted problem areas in order to encourage discussion. The 3‐day meeting was characterized by lively, broad‐ranging, often humorous discussion of a variety of problems. The following is a short synopsis of the major areas of d