The title compound, [Co(C(20)H(23)N(3)O(2))(C(5)H(11)N)](C(24)H(20)B) or [Co{(Me-sal)(2)dien}(pprdn)]BPh(4), where (Me-sal)(2)dien is 2,2'-[1,1'-(3-aza-pentane-1,5-diyldinitrilo)diethyl-idyne]diphenolate and pprdn is piperidine, contains a penta-dentate (Me-sal)(2)dien ligand furnishing an N(3)O(2) set, such that two of the N and one of the O atoms of the salicyl-idene rings define three positions of an equatorial plane, whereas the secondary amine N atom and the other O atom of the salicyl-idene lie in axial positions. The piperidine ligand occupies an equatorial position trans to one of the imine N atoms of the salicyl-idene. In the observed conformation of the penta-dentate ligand, the salicyl-idene rings attain asymmetrical positions owing to the structural demands. The geometry of the resulting CoN(4)O(2) coordination can be described as distorted octa-hedral. The asymetric unit contains two formula units.