The q23-q33 region of human chromosome 5 encodes a large number of growth factors, growth factor receptors, and hormone/neurotransmitter receptors. This is also the general region into which several disease genes have been mapped, including diastrophic dysplasia, Treacher Collins syndrome, hereditary startle disease, the myeloid disorders that are associated with the 5q-syndrome, autosomal-dominant forms of hereditary deafness, and limb girdle muscular dystrophy. We have developed a framework physical map of this region using cosmid clones isolated from the Los Alamos arrayed chromosome 5-specific library. Entry points into this library included 14 probes to genes within this interval and one anonymous polymorphic marker locus. A physical map has been constructed using fluorescence in situ hybridization of these cosmids on metaphase and interphase chromosomes, and this is in good agreement with the radiation hybrid map of the region. The derived order of loci across the region is cen-IL4-IL5-IRF1-IL3-IL9-EGR1-CD1 4-FGFA-GRL-D5S207-ADRB2-SPARC-RPS14+ ++-CSF1R- ADRA1, and the total distance spanned by these loci is approximately 15 Mb. The framework map, genomic clones, and contig expansion within 5q23-q33 should provide valuable resources for the eventual isolation of the clinically relevant loci that reside in this region.