The title compound, [Co(C(14)H(17)N(5))(C(6)H(7)N)](C(24)H(20)B) or [Co{(pyrrole)(2)dien}(4-Mepy)]BPh(4) where (pyrrole)(2)dien is 2,2'-[(3-aza-pentane-1,5-diylbis(nitrilo-methyl-idyne)]dipyrrole and 4-Mepy is 4-methyl-pyridine, contains a penta-dentate (pyrrole)(2)dien ligand furnishing an N(5) set, such that two of the pyrrole N atoms and two of the dien N atoms occupy the equatorial positions while one of the imine N atoms of the (pyrrole)(2)dien ligand occupies the axial position. The 4-methyl-pyridine ligand occupies an axial position trans to one of the imine N atoms of the penta-dentate ligand. In the observed conformation of the penta-dentate ligand, the pyrrole rings attain asymmetrical positions owing to the structural demands. The geometry of the resulting CoN(6) coordination can be described as distorted octa-hedral.