In India, north-east region holds a special position of having diverse range of plants belonging to endemic species with widespread ethnomedicinal properties which remain unexplored till date. In the present study, Eriobotrya bengalensis (Roxb.) Hook. f. extract was evaluated for its radical scavenging activity and ability to combat quorum sensing regulated bacterial virulence in Pseudomonas aeruginosa PAO1. The ethanolic leaf extract of E. bengalensis (Roxb.) Hook. f. exhibited a concentration dependent radical scavenging of highly reactive DPPH and hydroxyl radicals with a scavenging percentage of 76.84 ± 4.72 and 67.37 ± 4.35 % respectively at a concentration of 500 µg/ml. E. bengalensis (Roxb.) Hook. f. also showed significant reducing power and relatively high ascorbic acid equivalent. The plant extract was also evaluated for its ability to down-regulate the production of quorum sensing (QS) regulated pathogenic determinants in P. aeruginosa PAO1. The violacein production in Chromobacterium violaceum and pyocyanin production in P. aeruginosa PAO1 was greatly inhibited on treatment with sub-MIC of E. bengalensis (Roxb.) Hook. f. with an inhibition of 79.58 ± 4.13 and 76.31 ± 4.03 % respectively. The anti-biofilm activity was further confirmed by confocal laser scanning microscopic (CLSM) analysis. The anti QS activity of E. bengalensis (Roxb.) Hook. f. was further corroborated by molecular docking studies which provides an insight into the mechanism of QS inhibition. The present result will provide novel leads to the application of unexplored plant species towards the development of novel anti-infectives in the post-antibiotic era.