en عمومى General پژوهشي Research <strong>Background:</strong> Nonsteroidal anti-inflammatory drugs (NSAIDs) such as Aspirin may have anticancer properties, and can be effective as a novel strategy for the treatment of colorectal cancer (CRC). The aim of this study was to assess the cytotoxic effects of Aspirin drug in CRC cell lines compared with Oxaliplatin drug <em>in vitro</em>.<br> <strong>Methods:</strong> Cell viability was assessed after treatment of SW742 and SW480 cells with Aspirin and Oxaliplatin by MTT assay, and the amount of IC50 was determined. Statistical analysis was performed through one-way ANOVA and Tukey multiple range analysis (SPSS 19.0 software (P <0.05).<br> <strong>Results:</strong> Aspirin and Oxaliplatin considerably inhibited the growth of SW742 and SW480 cell lines. SW742 cell line was more sensitive to Aspirin than SW480 cell line. The cytotoxic effect of Oxaliplatin was higher than Aspirin in both cell lines.<br> <strong>Conclusions:</strong> This study demonstrated that both Aspirin and Oxaliplatin have cytotoxic effects on SW742 and SW480 cell lines in vitro. Thus, Aspirin may be considered as a therapeutic agent in CRC, however, further <em>in vivo</em> investigations are required to fully establish this effect. Aspirin, Colorectal Cancer, MTT Assay, Oxaliplatin 1 4 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-474-1&slc_lang=en&sid=1 Malihe Bagheri 100319475328460011351 100319475328460011351 Yes MSc of Medical Biotechnology, Student Research Committee, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran. Amir Reza Hesari 100319475328460011352 100319475328460011352 No PhD of Biotechnology, Molecular and Medicine Research Centre, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran. Parisa Zia Sarabi 100319475328460011353 100319475328460011353 No MSc of Medical Biotechnology, Molecular and Medicine Research Centre, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran. Hamid Reza Rahimi 100319475328460011354 100319475328460011354 No PhD of Molecular Medicine, Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. Maryam Baazm 100319475328460011355 100319475328460011355 No Department of Anatomy, School of Medicine, Arak University of Medical Sciences, Arak, Iran. Faezeh Ghasemi hasemi_f@arakmu.ac.ir 100319475328460011356 100319475328460011356 No PhD of Biotechnology, Molecular and Medicine Research Centre, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.