A series of bisbenzimidazole derivatives starting from o-phenylenediamine and 4-nitro-o-phenylenediamine were prepared with oxalic acid. Most of the reactions were conducted using both the microwave and conventional methods to compare yields and reaction times. The operational simplicity, environmental friendly conditions and high yield in a significantly short reaction time were the major benefits. All substances' inhibitory activities against alpha-glucosidase were evaluated. The results may suggest a significant role for the nature of bisbenzimidazole compounds in their inhibitory action against alpha-glucosidase. They showed different range of alpha-glucosidase inhibitory potential with IC50 value ranging between 0.44 +/- 0.04 and 6.69 +/- 0.01 mu M when compared to the standard acarbose (IC50, 13.34 +/- 1.26 mu M). This has described a new class of alpha-glucosidase inhibitors. Molecular docking studies were done for all compounds to identify important binding modes responsible for inhibition activity of alpha-glucosidase. (C) 2016 Elsevier Ltd. All rights reserved.