Introduction: Gadolinium based contrast agents (GBCAs) are widely used in magnetic resonance imaging (MRI). Recently, increased signal intensity has been reported in specific brain areas such as dentate nucleus, globus pallidus and cerebellum after repeated administrations of GBCAs. The aim of the present study was to investigate the toxic effects of GBCAs on neuronal cells by using SH-SY5Y neuroblastoma cell cultures. Methods: For toxicity assays, SH-SY5Y cells were seeded in 96-well dishes (5000 cells/well) and incubated with different doses (0-1000 µM) of several macrocyclic (gadoteric acid and gadobutrol) and linear GBCAs (gadoversetamide, gadopentetic acid, gadodiamide and gadoxetic acid) for 72 hours. Cell viability and mitochondrial metabolic activity were evaluated by using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay, colony forming assay and Hoechst staining. The results were expressed as mean ± SEM. The data was analyzed using student t-test. A p value <0.05 was accepted as statistically significant. Results: Both macrocyclic and linear GBCAs significantly and dose-dependently reduced cell viability in neuronal cells compared to untreated cells. Cell viability was measured between 89.49 ± 4.09 % and 60.99 ± 0.77 % in GBCAs-treated groups. In addition, neurotoxicity was more prominent in linear GBCAs-treated cultures (p<0.0005). Conclusion: The results of the present study indicate that exposure to specific GBCAs, even at low micro-molar concentrations, may have detrimental effects on neuronal survival. Further investigations are required to clarify the molecular mechanism underlying GBCAs-induced cell death.