Objective This study sought to investigate the possible association between clinical and radiographic data of the patients with the bacterial community profiles involved in cases of necrosis in primary root canals. Methods Microbial community profiles for 25 samples from necrotic deciduous root canals were analyzed using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting approach. These results were related to the clinical and radiographic data of these patients. Results The analysis showed a large diversity of microbial communities in necrotic deciduous root canals. The statistical results pointed out that posterior and anterior teeth were associated with 20 bands in PCR-DGGE method, respectively. A relationship was verified between ages >4 years old and posterior teeth and, ages ≤4 years old and anterior teeth. Conclusions The data showed a polymicrobial community and pointed out the association of age with necrosis in anterior and posterior teeth. © 2014 Published by Elsevier Ltd.