This document summarizes the health effects of smoking. It states that smoking is a learned habit that is culturally established, and is the leading cause of avoidable illness and death worldwide. Smoking causes over 60 million deaths between 1950-2000 in developed countries, and tobacco-caused deaths are expected to increase to 10 million per year by 2030, most occurring in developing countries. Half of regular smokers will eventually be killed by their habit.