The full-length coding sequence of the human erythropoietin receptor has been assembled from cDNA and genomic DNA. The derived 508 amino acid sequence is 82% identical to the murine erythropoietin (Epo) receptor with one single residue gap in alignment. There is no major structural difference between the human and murine receptor molecules. Nucleotide sequence homology is, as expected, very high within the coding domain. Unexpectedly, there are two distinct, short stretches of 3′ untranslated sequence homology between human and murine cDNAs. The functional significance of this sequence conservation is unknown. The human Epo receptor gene is localized to human chromosome 19p by in situ hybridization. This chromosome assignment is confirmed by hybridization to a panel of sorted human chromosomes.