Ashwagandha, having multiple therapeutic uses, is a highly valuable medicinal plant for pharmaceutical industry. In order to meet the industrial demand, both quality as well as yield of ashwagandha needs to be improved agronomically. In this study, effect of weed leaves extracts (WLE) as bio-stimulants to improve yield and quality of ashwagandha roots were studied in pot experiments during 2020-21. The treatments consisted of combinations of four commercial preparations with microorganisms (Pusa zinc solubilizing biofertilizer, Pusa Azotobacter liquid biofertilizer, Pusa PSB liquid biofertilizer, Pusa Potash solubilizing liquid biofertilizer) with four weeds [Cyperus rotundus L., Amaranthus viridis L., Echinochloa colona (L.) Link, Digera arvensis Forsk.] leaves extracts. The treated plants exhibited stimulatory responses in growth and physiology, leading to enhanced dry root yield of ashwagandha compared to control. Yield enhancing effects of different treatments, when used separately, without combination was the highest in case of Amaranthus viridis WLE, followed by Digera arvensis WLE and PSB solubilizing biofertilizer, however co-application resulted in synergistic effect. Among different combination of treatments, Pusa PSB liquid biofertilizer + Amaranthus viridis WLE recorded the highest whole ashwagandha plant dry matter production (157.3 g/plant), root fresh weight per plant (65.0 g) and root dry weight (23.0 g). Different bioactive compounds in ashwagandha roots (withanoloides A, withanosides IV and withanone) were also enhanced with this treatment indicating the potentiality of weed leaves extracts as biostimulants, with a possibility to use as a novel eco-friendly approach for enhancing root yield and quality of ashwagandha.