Objective: The identify and quantify, by high performance liquid chromatography, f lavonoids from leaf and stem extracts of Acer negundo.Design/methodology/approach: Ethanolic extracts of Acer negundo were analysed with high performance liquid chromatography to quantify and identify their major antioxidant f lavonoids.Results: Leaf extracts had high concentrations of rutin (34.19 g/mL) and catechin (33.97 g/mL), intermediate concentrations of apigenin (19.05 g/mL), gallic acid (19.04 g/mL), ferulic acid (17.2 g/mL) and 2.5 dihydroxybenzoic acid (12.72 g/mL), and low concentrations of caffeic acid (6.15 g/mL), quercetin-3--glucoside (4.97 g/mL) and isorhamnetin (4.68 g/mL). In the stemʼs extracts, the highest concentrations were of ferulic acid (7.96 g/mL), rutin (5.61 g/mL) and catechin (4.37 g/mL); medium concentration were identified for isorhamnetin (3.31 g/mL) and quercetin-3--glucoside (2.01 g/mL) and apigenin (0.79 g/mL) was identified at the low concentrations. Gallic acid, caffeic acid or 2,5-dihydroxybenzoic acid were not detected.Limitations/implications: Some f lavonoids have been identified in other Acer species but have not been identified and quantified in Acer negundo, a Mexican species.Findings/conclusions: For the first time we report gentisic acid in Acer negundo leaf extracts. This analytical method can be standardized to serve as a quality analysis of maple tree products.