The leaf and stem extracts of Boehmeria nivea (BN) collected from three different regions in Korea were screened for their antioxidant, neuroprotective, estrogenic, insulin secretion, and α-glucosidase inhibitory activity. We also examined whether BN extracts regulate cancer cell growth, inflammatory-related gene expression, and lipid accumulation in cellular system. Leaf extracts possessed greater antioxidant, anti-proliferative in cancer cells, neuroprotective, estrogenic activity, and inhibitory effect on pro-inflammatory gene expression than stem extracts. Leaf and stem extracts inhibited lipid accumulation in three T3-L1 adipocytes but did not affect glucose-stimulated insulin secretion in INS-1 cells. We isolated and identified the phytochemical constituents in the n-butanol and ethyl acetate fractions of BN leaves by combining silica gel column chromatography with mass spectrometry and 1 H- and 13 C-NMR analysis. The active compounds (caffeic acid, isoquercitrin, p-coumaric acid, and rutin) exhibited ABTS and DPPH radical scavenging activity, which may contribute to the biological activities of BN leaf extract. An analytical method was developed to quantify marker compounds for the discrimination of BN collected from different regions. Our results support the use of this analysis method for accurate identification and quantification of marker compounds in BN for the development of functional foods. PRACTICAL APPLICATIONS: Boehmeria nivea (BN) has been used as a raw material for the textile industry or traditional herbal medicine. The current study established the biological activities and active components of BN. Our results showed that BN leaf and stem extracts exhibit antioxidant, neuroprotective, and estrogenic activity. BN leaf extract also inhibited cancer cell growth, inflammatory mediators and cytokines production, and lipid accumulation in vitro. Moreover, the bioactive compounds, such as caffeic acid, isoquercitrin, p-coumaric acid, and rutin, exert ABTS and DPPH radical scavenging activities. Therefore, BN could potentially be a promising source of bioactive phytochemicals for the development of functional foods or drugs.