The present study aimed at producing ZnO nanoparticles using the leaf extract of nettle ( Urtica dioica ) as a medicinally valuable plant to maximize the antidiabetic property of ZnO while excluding the chemical pollution from the synthesis process. The properties of the ZnO-extract sample were uncovered by var- ious techniques and compared to that produced without the extract (ZnO). The results of the surface, optical, and thermal studies disclosed the presence of the extract biomolecules over the ZnO-extract sam- ple and was further confirmed by GC-MS analysis. The ZnO-extract was intraperitoneally injected to alloxan-induced diabetic rats and the effects on the serum levels of fasting blood glucose, insulin, high-density lipoprotein cholesterol, total cholesterol, and total triglyceride were assessed. The obtained results were then compared with the effects of ZnO, nettle leaf extract, and insulin on the same factors. Among all the examined treatments, the best antidiabetic performance was obtained in the rats treated by ZnO- U. dioica extract mainly owing to the great synergistic interaction between its constituents. (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.