Objective As part of the Smoke-Free Illinois Act, smoking on the gambling floors of all commercial casinos in Illinois became prohibited. This study examined the effects of the Smoke-Free Illinois Act on casino admissions per-capita and real per-capita adjusted gross receipts using 18 years of data (10 years before and 8 years after the Illinois law went into effect).

Methods We employed a difference-in-difference regression technique using monthly data for the states of Illinois, Indiana, Iowa and Missouri and control for numerous determinants expected to affect casino admissions and revenue.

Results The Smoke-free Illinois Act was found not to be a statistically significant determinant of per-capita casino admissions and of real per-capita gross adjusted receipts in all the models we estimated.

Conclusions The estimates from this study clearly indicated that the Illinois law that banned smoking in casinos has had no significant negative economic consequences for casinos in terms of per-capita admissions or revenues.