The magnetic properties of 4d monoatomic rows on Ag substrates have been studied by ab initio calculations using the screened Korringa-Kohn-Rostoker ͑SKKR͒ Green's function method within density functional theory ͑DFT͒ in its local spin density approximation ͑LSDA͒. The rows were placed at step-edge ͑step decoration͒ and on terrace positions of different vicinal Ag surfaces, i.e., fcc ͑711͒, fcc ͑410͒, and fcc ͑221͒. The results for the magnetic moments are explained in terms of the different coordination numbers of the row atoms and the different hybridization between the rather extended 4d orbitals of the row atoms and the sp-like valence electrons of the Ag substrates. For the fcc ͑711͒ vicinal surface, we explore the possibility of antiferromagnetic coupling between the atoms in each row and discuss, by means of total energy calculations, the stability of the antiferromagnetic solutions with respect to the ferromagnetic ones.