Cancer accounts as one of the leading causes of morbidity and mortality. Recent studies focus on the efficiency of phytochemicals in cancer therapy. Influence of quercetin, a flavonoid on the effect of γδ T cells and Wnt/β-catenin signalling pathway in human colon cancer cells (HT55 and HCT116) was investigated. Quercetin at 15-120 µM was observed to markedly reduce the viability of HT55 and HCT116 cells. Quercetin exposure significantly increased γδ T cell proliferation and also raised the expressions of granzyme B (Gra B), perforin (PFP), and interferon-γ (IFN-γ) in γδ T cells. Reduced β-catenin expression with increased expressions of phosphorylated-β-catenin, axin1 and 2 were observed in HT55 and HCT116 cells on exposure to quercetin. However β-actin expression was found to be not much altered. The results suggest that quercetin was able to efficiently potentiate the effect of γδ T cells and modulate Wnt/β-catenin signalling pathway. [ABSTRACT FROM AUTHOR]