The use of plant stem cell extracts as active ingredients in cosmetic formulations has gained popularity recently, highlighting the need to establish Impatiens tinctoria A. Rich in vitro cultures in order to prepare bioactive stem cell extracts. This study is aimed at establishing cell suspension culture and evaluates the antioxidant activity of the stem cell extract. In order to initiate callus and cell suspension cultures, tuber explants were inoculated onto Murashige and Skoog (MS) media containing 2,4-D (0.5–2 mg/L) and BAP (0–2 mg/L). Optimal hormone concentrations of 2 mg/L 2,4-D and 1.5 mg/L BAP were sufficient to produce callus. The obtained callus was utilized as the inoculum to start a cell suspension culture for the production of stem cell extracts. High biomass accumulation was obtained at 30 g/L sucrose concentration and 6g inoculum size. The stem cell extract had a total phenolic content of 4.6 µgGAE/mL and a flavonoid content of 190.96 µgQE/mL. DPPH scavenging activity of 95.82% and the IC50 value of 37.54 µg/mL was detected for the stem cell extract. The study indicated that the suspension cultures of I. tinctoria A. Rich have the potential to produce stem cell extracts with increased flavonoids content and antioxidant activity.