The downpour of information about the H-2 complex has hit immunology with the force of a tropical rainstorm. It is flooding whole fields, uprooting carefully cultivated orchards, displacing cottages, houses, and palaces, threatening to drown their inhabitants. This and the following article (Klein et al. 1982) are meant to serve as kinds of life-savers for those who have not learned how to swim in the rapid and murky waters. The First Listing, published four years ago (Klein et al. 1978), consisted only of tables; to this Second Listing we have added a brief description of all the loci residing, or thought to be residing, on the mouse chromosome 17, the chromosome carrying the H-2 complex. This arrangement necessitated the division of the Second Listing into two parts, the first part concerned with loci on chromosome 17 outside of the H-2 complex and the second part dealing with the complex itself. The discussion of the individual loci is prefaced by a description of the chromosome.