During December 31, 2004–December 31, 2007, based on the effective date of state laws (ie, the date that these laws actually took effect, not the date they were enacted) and the STATE System coding scheme, the level of smoking restrictions became more protective for private-sector worksites in 18 states, for restaurants in 18 states, and for bars in 12 states. No states relaxed their smoking restrictions in any of these three settings during the study period. In addition, the number of states requiring private-sector worksites to be smoke-free increased from five to 22. As of December 31, 2004, Delaware, Florida, Massachusetts, New York, and South Dakota had banned smoking in private-sector worksites. As of December 31, 2007, an additional 17 states (Arizona, Arkansas, Colorado, DC, Hawaii, Louisiana, Minnesota, Montana, Nevada, New Jersey, New Mexico, North Dakota, Ohio, Rhode Island, Tennessee, Utah, and Washington) had done so. During the study period, the number of states with no smoking restrictions in place for private-sector worksites decreased from 24 to 13.