Abstract: The aim of this study was to investigate the responses of the nitrogen compounds in the cultivars México 222 (resistant) and Widusa (susceptible) of Phaseolus vulgaris L. plants inoculated with Colletotrichum lindemuthianum race 23. The experimental design used was entirely randomized in factorial scheme, with 2 cultivars (México 222 and Widusa) and 2 treatments (control and inoculated). The compounds evaluated were free ammonium, amino acids, proline and total soluble proteins. The proline level suffered significant increase only in cultivar Widusa, which the increase showed was at 18.9% in plants under pathogen inoculation, when compared with the control plants. The total soluble proteins level in Mexico 222 had significant increase, with the control and inoculated plants presented 4.77 and 6.60 mg g DM-1, respectively. The results revealed that the Widusa cultivar (susceptible) suffered significant changes in free ammonium, total soluble amino acids and proline, however the total soluble proteins level was kept stable. The Mexico 222 cultivar (resistant) presented not significant modification only in proline level. In addition, this study proved the strong influence of the Colletotrichum lindemuthianum pathogen on the nitrogen metabolism of Phaseolus vulgaris plants.