Lung cancer is one of the most common causes of death.It is known that genetic reasons in its etiology.Lung cancer has been shown to be associated with the EGFR,P53,KRAS and c-MYC genes.Thymoquinone is an antitumoral and antineoplastic bioactive substance procured from Nigella sativa plant.Cisplatin is a frequently used chemotherapeutic agent in the treatment of lung cancer.Our study has been conducted to examine the effects of Tq and Cis on gene expressions on lung cancer cell lines.Potential effects of Tq and Cis on A549,HTB54, CRL5820 and BEAS2B cell lines and cell viability using MTT has been evaluated.Cell culture has been effectuated with RPMI supplemented with 10% FBS,1% antibiotic and DMEM(37°C, %5 CO2).Cells were cultured for 24 h in 96 well plates(2500/ml cells) 10% FBS RPMI appropriate medium.The cells have been exposured 100 μM Tq and 200 μM Cis for 4h under incubation conditions.DMSO has been used for negative control.RT PCR has been conducted using SYBR Green qPCR Master Mix(reference gene GAPDH).As a result, p53 gene suppression has been shown in lung adenocarcinoma with Tq and Cis and epidermoid carcinoma with Cis only.EGFR gene suppression has been shown in lung adenocarsinoma with Tq only and epidermoid carcinoma with Cis only.C-MYC gene suppression has been shown in lung adenocarsinoma with both substances(more at Tq).It has been shown that KRAS gene suppression does not occur in any cell line.In addition, it has been shown that no gene expression is suppressed after Tq and cis exposure in the mesothelioma cell line.