A large number of disposable medical devices (DMD) are being used every day. In this regard, one of the most important issues is the safety of these tools for patients. In this study, the cytotoxicity of different DMD from different brands was investigated. We studied the cytotoxicity of extracts of DMD including intravenous transfusion sets (IVTS), intravenous infusion set (Microset) and syringe using L-929 cells. Alterations in cell morphology and viability were evaluated using light microscopy and the MTT ASSAY, respectively. Findings of the study demonstrated that 20 percent of IVTS samples, 10 percent of microset samples and 5 percent of syringe samples were cytotoxic. In this regard, four cytotoxic IVTS induced about 95%, 88%, 84% and 79% lethality in treated L929 cells. Also, two cytotoxic microset samples induced 74% and 65% lethality in treated L929 cells and a cytotoxic syringe sample induced 71% lethality in treated cells. Microscopic evaluation showed that treated cells with the toxic samples were damaged and there were no normal morphology and cell growth. We conclude that some DMD are toxic and as a result they could be hazardous for human health. We strongly believe that before clinical use of these medical devices, their biocompatibility must be evaluated by certified laboratories.