The health effects of secondhand smoke have recently been called into question. However, there is a substantial body of evidence supporting the existence of these effects. The main effects in adults are an approximately 25% increase in the risk of ischemic heart disease and lung cancer. In children, exposure to tobacco smoke increases the risk of sudden infant death syndrome, respiratory infections, ear infections, and asthma. Before the ban on smoking in public places, secondhand smoke was responsible for several hundred deaths each year in France. Recent legislation reducing exposure to tobacco smoke is a good measure if it is enforced. (R.A.)