This report presents information on advances of the CIMMYT Maize Program (CMP) during 1982-83. The report includes the following sections: description of the CMP germplasm bank accessions; characteristics and evolution of gene pools (tropical and subtropical, temperate, and highland pools) pointing out the main breeding aims for each group and the role of the introduction nurseries to incorporate new germplasm into the pools; description of the activities of CMP Advanced Unit which is responsible for forming advanced populations, improving them, and extracting experimental varieties from them; description of the structure of78 pages