Nonalcoholic fatty liver disease (NAFLD) is the most common cause for elevated liver enzymes in the developed nations. Beyond prevention programs which are of particular interest because of the increasing number of overweight children, treatment should be focussed on the most important risk factors, obesity and insulin resistance. As a consequence of elucidating the pathomechanisms of NAFLD, the number of potential therapeutic options increased. However, many studies investigating the therapeutic effect show shortcomings in at least one of the following points: lack of a serial liver biopsy, short term of treatment and limited number of included patients. The second generation insulin sensitizer pioglitazone and rosiglitazone show the most promising improvements in NAFLD, but weight gain and potential hepatotoxicity calls for attention. In conclusion, a general recommendation for the application of specific drugs cannot be given. Besides controlled clinical trials, weight reduction and physical activity to improve insulin sensitivity in obese patients should be the priority objective.