This research work intended to give readers a sense of FDA (Food and Drug Administration) activity and oversight of quality system regulation in terms of warning letter issued to medical device companies. The study analyzes the quality issues and trend contained in warning letters issued to medical device manufacturers by the FDA. FDA’s online Warning Letter Index was reviewed for warning letters issued specific to Medical Device Manufacturers from different countries under the violation subject “cGMP/QSR/Medical Device/Adulterated, Medical device reporting regulation/Misbranded, cGMP/QSR/Manufacture/Packing/Storage Installation/Adulterated” for the period January 2008 through December 2009. The resultant 137 warning letters were reviewed and number of citations of the individual paragraphs of 21 CFR (Code of Federal Regulation) Part 820 Quality System Regulations was calculated. This study identified ten different FDA regulated areas in which most medical device companies commonly received enforcement letter. Quality control tool such as Pareto chart analysis was used to find the highest cited FDA regulated area. Among which CAPA identified as the 1st deficiency, especially Part 802.100 (a) (3), “Identifying the action(s) needed to correct and prevent recurrence of nonconforming product and other quality problems” was exceedingly cited by FDA. This was followed by deficiencies in Part 820.198 (a), lack of established procedures for evaluating complaints received to determine whether or not the complaint should be filed as a Medical Device Report. Deviations regarding Design validation are at 3rd position. FDA cited medical device companies that did not have a procedure for validating the device design as well as failure to perform risk analysis study while performing validation study. Warning Letters are very informative tool with regards to the evaluation of focal points in FDA’s inspection. These letters are important as they show what specific things FDA looks at while inspecting the facilities.