The aim of this experimental study was to analyze in vitro effects of clofibric acid on vimentin and desmin contents in rat myocardiocytes, which was carried out in primary myocardiocyte cells that were treated only with clofibric acid at 0.1 mM. The measurement of vimentin and desmin were done by Western blotting and densitometry. This study showed that myocardiocytes exposed to clofibric acid exhibit a 26.3% decrease in vimentin and a 42.1% decrease in desmin. Considering the role that these intermediate filaments play in the anchorage and cellular organization of myocardiocytes, the decrease of desmin and vimentin observed in cells treated with clofibric acid may be partially responsible for the adverse effects observed in patients. In conclusion, the alteration of cytoskeletal proteins may be a cause of cardiopathy in patients treated with these compounds.