An alternative simple method to evaluate the L/D ratio of neutron imaging beams is proposed. It is based on the behavior of the ratio ???x/Ut???, which asymptotically tends to L/D for large values of the parameter ???x???, that corresponds to the distance separating a gadolinium test object to the scintillator plane, where its image is formed. The method was applied to the neutron imaging equipment of the Nuclear and Energy Research Institute IPENCNEN/ SP and the obtained result was L/D = (104 ?? 4). The consistency of the proposed method was verified by comparing this value with those ones obtained by a well - known and established procedure.