Background Antimicrobial resistance is peaking up all over the world and requires immediate attention. In quest of finding a sustainable solution to the present threat of future epidemics which is going to be caused by Acinetobacter baumannii (A. baumannii) as per the WHO report (2020), this study has been used to pave a path for finding an herbal solution to it. The novelty of this study is that Valeriana wallichii (V. wallichii) has been analyzed for its methanolic extract/nano-conjugate against A baumannii. Results HPLC of the extract has shown the presence of polyphenols- Quercitin, Rutin, and Tannic acid in high concentration. This fraction on nano-conjugation with silver has shown its equivalence to tetracycline antibiotics in restricting the growth of A. baumannii. Further, insilico studies taking crucial death receptors (Amp C, Fab1, RstA, LpxA, Aspartokinase, and shikimate dehydrogenase) of A. baumannii have shown binding energy ranging from − 11.6 to -13.3 kcal/mol for Tannic acid and close to this for Rutin and Linalool. It signifies that the fraction is potent enough to be a potential drug candidate for restricting this bacterium. The results were amazing when V. wallichii silver nanoconjugate (Vw-AgNCs), size range 1-200nm validated by DLS, AFM, and SEM-EDX on green synthesis has many times substantially enhanced restriction of A. baumannii as compared to only extract of V. wallichii. Keeping in view, its application to mankind, the cytotoxicity of the extract was evaluated on the human Fibroblast cell line (L929), showing an LC50 value of 368ug/ml. Many types of research have shown the time-dependent cytotoxicity of antibiotics as low as 5-50ug/ml providing us with a huge therapeutic window for the Vw-AgNCs. Conclusion Vw-AgNCs exhibited strong antimicrobial activity than the only extract and chemically synthesized nanoparticles so they can be a potential antimicrobial agent against A. baumannii in the future.