Hepatitis C virus (HCV) infects ~ 3% of world population with significant mortalities in developing countries. If HCV disease goes untreated, it can lead to cirrhosis, hepatocellular carcinoma and ultimately death of the patient. Currently in Pakistan, about 5 to 10% of population is infected with HCV. This book provides useful informations about diagnostic, prevalence and drug discovery initiative against HCV genotype-3a (HCV-3a), the most prevalent genotype in developing world, particularly in South Asia including Pakistan. Drug discovery imitative is pursued by exploring the expression, purification and characterization of HCV-3a proteins such as NS3, NS5A and N5B, which are the targets of antiviral drugs. The newly developed direct acting antiviral drugs are less effective against HCV-3a as compared to genotype-1, therefore , studies describe in this book will help the relevant scientific professionals in designing better strategies to develop potent drugs against HCV-3a. From both, pharmaceutical market or human life saving point of views, there is a huge potential to develop cost effective and safer drugs to treat life-threatening disease caused by HCV.