Child safety seats provide an effective means for protecting children in car crashes. Without legislation, few States have been able to obtain usage rates greater than the 20-30 percent range. As a result, 40 States, the District of Columbia, and five Canadian Provinces have now passed child passenger safety laws. These laws vary considerably from State to State. The most important provisions and variations among these laws are summarized in this paper. Since only 19 State laws have been in existence for six months or more, unequivocal data concerning their effectiveness is not yet available. However, initial data gathered on both a national (19 city) level and in various States suggests that these laws are effective in terms of raising usage rates and lowering deaths and injuries to young children. Much needs to be done, however, to realize the full potential of such legislation. Specifically, education, loan-a-seat programs, and most importantly, enforcement must be improved and promoted.