Iris taochia is an elegant endemic plant in Türkiye and it has limited distribution. In this study, cytotoxic effects of ethanolic extracts from different parts and concentrations extracted from I. taochia collected from the surroundings of Tortum (Erzurum), on A549 human lung adenocarcinoma cell line were investigated. Cytotoxicity of extracts were evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) method. Apopototic activity of IC50 values of extracts were evaluated with Annexin V and Caspase 3/7 assays. Ultrastructural changes of IC50 doses treated cells were investigated by transmission electron microscopy. As a result, it was determined that ethanol extract of I. taochia showed significant cytotoxic activity on A549 cells after 24 hours the extract a dose-dependent reduction in cell viability. IC50 values of above and below ground parts ethanolic extracts were determined as 7 µg/ml and 20 µg/ml respectively. Specifically, apoptosis inducing effect was increased at 7 and 20 µg/ml concentrations by 24 hours. We found that I. taochia ethanol extracts had antiproliferative and apoptotic effects on the human lung adenocarcinoma cells A549. However, further studies at molecular level are required to support our findings and to elucidate chemoproteventive and chemotherapeutic effects of I. taochia on lung cancer.