Hospitals and health care providers are striving to reduce health care cost without compromising the quality of health care and appropriate medical diagnosis. They are becoming more aware of the importance of medical devices calibration in their health care facilities, and the impact it has on both the quality of health services provided to the patients, and patient's safety. Healthcare providers are beginning to realize that the maintenance of medical devices alone, without assuring proper calibration, may not be sufficient enough to ensure proper function, adequate and reliable measurements. Accurate and reliable measurements are crucial for appropriate medical decisions. On the contrary, un-calibrated medical devices may lead to imprecise measurements. These measurements will have a significant negative impact on the quality of the healthcare provided to patients and might increase the healthcare cost by subjecting patients to excessive medical treatment. The study was conducted on a representative sample of 20.5% from total asset (1034) of high risk medical devices representing 6 devices categories. The objective of this study is to examine the impact of calibration of medical devices on performance and patient's safety by investigating devices performance against international standard reference or manufacturer recommendations. 34% of the sample failed the visual test, 5% failed the safety test, and 58% failed the performance test. However, it is important to note that there was no death or serious incidents associated with these devices. In conclusion, these devices do not meet the international standard and continued use of such devices can compromise patient's safety.