Objective: The discovery of new natural resources with antidiabetic potential, weight control and antioxidant effect is one of the important targets in phytotherapy applications. In this study, the antioxidant, antidiabetic, antihyperlipidemic, and antiobesity activities of 80% ethanol extract of the aerial parts of Nasturtium officinale were evaluated. Qualitative and quantitative analyzes of the phenolic content of the extract were performed using spectroscopic and chromatographic methods Material and Method: In order to determine the antioxidant effect of the extract, DPPH and ABTS radical scavenging activity, metal chelating, total antioxidant capacity and reducing power were investigated. To evaluate the antidiabetic effect potential of the extract; α-glucosidase and α-amylase enzymes, pancreatic lipase enzyme for its antiobesity effect potential and pancreatic cholesterol esterase enzyme for its effect potential on lipid metabolism were used. While UV spectroscopy was used for total phenol and flavonoid content analysis of the extract, Reverse Phase-HPLC technique was used for qualitative and quantitative analysis of phenolic compounds. Result and Discussion: While Nasturtium officinale ethanol extract caused 81.80 ± 1.14% inhibition at 2 mg/ml concentration in DPPH radical scavenging activity method, the ferric reducing power of the extract was determined as 0.896 ± 0.020. In terms of antidiabetic effect, the extract showed the highest efficiency by inhibiting the α-amylase enzyme at a concentration of 2 mg/ml by 39.11% ± 2.98%. It was determined that the extract (42.18 ± 5.22%) had an inhibition on pancreatic lipase enzyme close to orlistat (65.13 ± 1.24%). As a result of Reverse Phase-HPLC analysis, both qualitative and quantitative analyzes of chlorogenic acid, caffeic acid and ellagic acid were performed. It was determined that the extract contains the most chlorogenic acid (0.079 ± 0.000% g/100g extract). While the findings indicate that the plant can be a source of natural product development studies for obesity control and that this effect can be evaluated with further in vitro and in vivo studies, it is predicted that chlorogenic acid can be used in the standardization of the extract.