Citrus canker, caused by Xanthomonas citri subsp. citri, is one of the most destructive bacterial diseases affecting acid lime cultivation. The present trials were undertaken to evaluate the pathogenicity of four isolates of Xanthomonas axonopodis pv. citri (Xac1, Xac2, Xac3 and Xac4) on different plant parts of acid lime (Citrus aurantifolia Swingle) - namely leaves, stems, fruits and thorns - and to assess pathogenic variability among isolates using an attached leaf technique under screenhouse conditions. The inoculation resulted in characteristic citrus canker symptoms including watery translucent spots, corky raised lesions and yellow halos. Leaves were found to be the most susceptible plant part, exhibiting the shortest incubation period across all isolates. Among the four isolates tested, Xac2 proved to be the most virulent, producing symptoms earliest (4 days on leaves) with the shortest average incubation period, while Xac4 was the least aggressive. Significant pathogenic variability was observed among the X. citri subsp. citri isolates, highlighting the importance of selecting virulent isolates for resistance screening and disease management strategies.