Changes in different regions of the brain due to postural disturbances were found in patients with chronic low back pain (LBP). The aims of the current study were to investigate the short- and long-term enhancing effects of concurrent postural training and primary motor cortex (M1) anodal transcranial direct current stimulation (a-tDCS) on balance, postural stability and pain in chronic LBP patients with postural impairment. In this clinical trial study, thirty eight patients with chronic LBP were randomly assigned to a-tDCS and training, sham a-tDCS and training,and training only groups. All groups received identical postural training for 20 min, three sessions per week for two weeks. The length of stimulation, which used concurrent with postural training in the active a-tDCS group was also 20 min. Before, immediately and one-month after the interventions, postural stability, balance and pain were assessed using Biodex Balance System, Berg Balance Scale (BBS) and Visual Analog Scale (VAS), respectively. The postural stability indices, BBS and VAS scores significantly improved immediately and one-month after the intervention in the a-tDCS and training group (P < 0.001), while there were significant differences between active a-tDCS and other two groups (P < 0.001). Postural stability indices, the BBS and VAS scores were not significantly different between the sham and training only groups after the interventions (P > 0.05). M1 a-tDCS significantly improves the effects of postural training on postural stability, balance and pain in patients with chronic LBP. Two-week postural training alone cannot improve postural impairment in patients with chronic LBP.