The role of statins in primary and secondary prevention of cardiovascular incidents cannot be questioned. However, it is commonly known, that their use, especially in high doses, can cause side effects. Our study reports the case of female patient who because of an episode of unstable angina underwent the percutaneous coronary intervention (PCI) of right coronary artery (RCA), and afterwards received the hypolipemic treatment of simvastatin in the dose of 80 mg/day. After the PCI she participated in the programme of early sanatory cardiac rehabilitation. After some days of her stay she started to notice the generalized muscle pain, that she initially linked with the intensification of exercise. Two days after finishing the rehabilitation programme she was admitted to our Department with the symptoms of generalized muscle injury. Laboratory test revealed very high serum level of creatine kinase, myoglobin and transaminases. Data obtained from anamnesis and results of laboratory testing enabled to diagnose myopathy being the result of hypolipemic treatment with high dose of simvastatin. After the treatment we observed gradual regression of muscle pain, and in 12th day of the stay in our clinic the normalization of biochemical parameters was stated. Our patient reported she was not informed about the possible complications of undertaken treatment. This case report emphasizes the necessity to precisely inform the patients about the possible drugs side effects.