  We carefully investigate the reliability of the propagator Pole
Approximation, i.e, the approximation of retaining only the propagator in the
evaluation of the Mandelstam covariant expression for the eletromagnetic
current of the pion. Different frames are analyzed, in order to find the most
suitable one for calculating the pion form factor within the proposed
approximation. It turns out that approximation is more accurate in the frame
where q^+ is maximal. The relevance of the Pole Approximation is briefly
discussed in view of calculations of hadrons factors basead wave functions
generate by dynamical models.
