The effective electron Lande factor in GaAs-Ga1-xAlxAs rectangular quantum well wires, under magnetic fields applied along the wire axis, is studied by taking into account the non-parabolicity and anisotropy of the conduction band within the Ogg-McCombe effective Hamiltonian. Confinement effects on the electron wavefunctions are explored in order to evaluate its influence on the behavior of the effective Lande factor. Calculations for the electron g(parallel to) factor in GaAs-Ga1-xAlxAs rectangular quantum well wires are compared with the previous theoretical results obtained for GaAs-Ga1-xAlxAs cylindrical quantum well wires. Such comparison clearly indicates the influence of the wire shape on the electron Lande factor in GaAs-Ga1-xAlxAs quantum well wires. (C) 2008 Elsevier B.V. All rights reserved.412240244