A new series of 3-benzyl-2-substituted quinoxalines have been synthesized by means of microwave enhancement of nucleophilic substitution reaction involving the corresponding 2-chloroquinoxaline analogs and substituted amines or hydrazine. The synthesized compounds were evaluated for their monoamine oxidase A and B inhibitory activity by determination of their IC(50). All the newly synthesized compounds showed more selective inhibitory activity toward MAO-A than MAO-B. In addition, the acute toxicity of the synthesized compounds was determined. This work may be a fruitful matrix of the synthesis of a new series of novel MAO-A inhibitors with good safety margins.