In our study, we planned to examine the effects of chemical substances on lung cancer cell lines. It is stated in the literature that cisplatin is effective in the treatment of lung cancer. Therefore, in this study, the effects of thymoquinone and cisplatin on lung cancer cell lines were investigated. Lung cancer diagnosis is late. Without symptoms, a nodule in the lung may grow or spread out of the lung. Therefore, 80% of these patients cannot be operated. This situation led to the need to study different molecules in the investigation of nonsurgical treatments. In our study, lung cancer cell lines; A549 (bronchioloalveolar carcinoma), HTB54 (epidermoid carcinoma lung), BEAS2B (bronchus epithelium),that reproduced with passaging by cell culture, were exposed to thymoquinone (tq) and cisplatin (cis) and the effects of different molecules on cancer cells were investigated. A549, HTB54, and BEAS2B were reproduced in culture medium and thymoquinone and cisplatin were administered at 10, 100, and 200 μM concentrations. Live cell determination was determined by MTT (3- (4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide). After MTT was evaluated at 550 nm with a spectrophotometer. The effects of 100 and 200 μM doses of thymokinone in A549, HTB54 and BEAS2B cells were higher than cisplatin effect at the same doses. Cisplatin has no effect at a dose of 100 μM in HTB54, and A549 cells. Both chemicals are effective at 100 and 200 μM doses in BEAS2B cells. The determined effective dose of thymokinone was 100 μM and cisplatin was 200 μM. Both chemicals have similar toxicity at effective doses. As a result, the effect of thymokinone on lung cancer cells was superior to the effect of cisplatin.