Receptors for atrial natriuretic peptide (ANP) in isolated bovine adrenal chromaffin cells were characterized. 1 2 5 I-ANP specifically bound to the cells with a K d of 103 pM and a B m a x of 5.6 fmol/10 6 cells (16.4 fmol/mg of cell protein). C-ANF, a highly selective ligand for ANP-C receptors of natriuretic peptides, did not compete for 1 2 5 I-ANP binding at concentrations up to 10 nM. Chemical cross-linking of 1 2 5 I-ANP to the cells showed a single molecular size of the 120 kDa binding site on SDS gel electrophoresis under reducing conditions. CNP, a specific peptide for the ANP-B receptor, was much less potent than ANP in inhibiting 1 2 5 I-ANP binding and in displacing 1 2 5 I-ANP from the 120 kDa band. These results suggest that ANP specifically binds to the ANP-A receptor of 120 kDa and that there is no ANP-C receptor in bovine adrenal chromaffin cells.