The Non-alcoholic fatty liver disease (NAFLD) affects the 30% of worldwide population with greater incidence (60-80%) in type 2 diabetic patients and progresses to not alcoholic steatohepatitis (NASH) with subsequent severe outcome (fibrosis cirrhosis, liver cancer). Several clinical studies showed that bile acids administration at sustained dosages can improve the NAFLD syndrome counteracting it’s worsening and death risk; we thus planned to compare the benefits and side effects of oral versus intravenous treatment of UDCA on 100 overweight not-diabetic volunteers (41 males and 59 females), with strictly similar biochemical–clinical expressions of nonalcoholic fatty liver disease (NAFLD). The patients were divided in two groups: one with 50 mg / kg /daily/os and the other with 3500 mg in 500ml saline perfusion each other day (except the weekend) for a total of 24 intravenous sessions. The results in terms of tolerability, symptoms relieve, and liver enzymes improvement defined the parenteral treatment as the most effective, being the oral burden somehow troublesome with some untoward effects not appearing in the intravenous route.