We have constructed a continuous Index map of 25 micosatellite markers on human chromosome 11. The markers have been typed in 40 CEPH families, have heterozygositles of 69% or higher and can be typed by PCR. The odds against inversion of adjacent marker loci order are at least 105: 1. The sex average map covers a total of 162 cM with no gap exceeding 15 cM. Total lengths for female and male maps are 205 and 123 cM, respectively. By use of a hybrid cell panel or by in situ hybridization, 16 of the markers have also been mapped cytogenetically, providing a good correlation of the Index map with the cytogenetic map. The map will facilltate high resolution mapping of additional polymorphic loci and of disease genes on chromosome 11.