The chromosomal assignments of the genes coding for the alpha, beta and delta subunits of the human nicotinic acetylcholine receptor have been determined from a panel of somatic cell hybrids and by direct in situ hybridization. The results localize CHRNA to 2q24-2q32. CHRNB to 17p11-17p12, and CHRND to chromosome 2q33-2qter.