In our study, the cytotoxic effect of paclitaxel (PAC) in tumor and normal cell lines were established; and chemoprotective effects of amifostine (AMI) and cysteamine (CYS) against this effect were examined. Tumor cell lines used in this study were L-strain cells and HeLa cells. Mouse embryonic fibroblasts (MEF) were used as normal cell line. Results of the experiments were evaluated with growth rate parameter. In the experiments, PAC concentrations of 6 and 12 mu g/mL were applied to the whole cell lines for 1-10 days, either alone or in combination with 1 mu g/mL concentration of AMI and CYS. A statistically significant effect were not determined in the whole cell lines, for the test groups in which 1 mu g/mL of AMI and CYS concentrations were applied solely. PAC concentrations caused increasing cytotoxic effect with increasing treatment time (p < 0.05). The effect of PAC on repression of cell reproduction appeared to be different in normal and tumor cells. In comparison to turner cells, MEF cells appeared more resistant to the decreased cell reproduction caused by PAC. HeLa cells were the most sensitive among tumor cells. In the MEF cell line AMI and CYS were cytoprotective. This cytoprotectivity exerted by these agents and the toxicity exerted by PAC alone appeared at the same time period. As a result, PAC continued to show its cytotoxic effect in tumor cells where AMI and CYS were used in combination. In contrast, this effect disappeared in normal cell line. In our study, AMI and CYS did not protect tumor cells, but the protection was observed in normal cells. This study was conducted to understand whether the interaction of the cytoprotective agents AMI and CYS with the chemotherapy agent PAC play role on growth rate. It was also assessed to what extent the cytotoxic and protective effects were agonistic or antagonistic in tumor or normal cells.