Geometries and energy separations of the various low-lying electronic states of Nb-n(+) (n=3-5) clusters with different structural arrangements have been investigated. The complete active space multiconfiguration self-consistent field (CASMCSCF) method followed by the multireference singles plus doubles configuration interaction (MRSDCI) that included up to 13 million configuration spin functions have been used to compute several electronic states of these clusters. A (5)A(2) isosceles triangle geometry in C-2v symmetry and a (2)A' pyramid structure in C-s symmetry are computed as the ground states of Nb-3(+) and Nb-4(+) clusters, respectively. In the case of Nb-5(+), a (1)A' state of distorted edge-capped tetrahedral structure (in C-s symmetry) was found to be the ground state. We also compared our MRSDCI results with density functional calculations. The dissociation and atomization energies have been calculated at the MRSDCI level and the results have been found to be in agreement with experimental findings.