Physical inactivity has reached epidemic levels in developed countries and is being recognized as a seriouspublic health problem. Recent evidence shows a high percentages of individuals worldwide who are physicallyinactive, i.e. do not achieve the WHO’s present recommendation of 150 minutes of moderate to vigorous intensityper week in addition to usual activities. Living in sedentary lifestyle is one of the leading causes of deaths and ahigh risk factor for several chronic diseases, like cancer, cardiovascular disease, diabetes type 2, and osteoporosis.This article summarizes evidence for relative risk of the civilization diseases attributable to physical inactivity andthe most important conclusions available from the recent investigations computing the economic costs specificto physical inactivity. The findings provide health and economic arguments needed for people to understand themeaning of a sedentary lifestyle. This may be also useful for public health policy in the creation of programmesfor prevention of physical inactivity.