​Trends in cigarette smoking were studied from 2001 to 2012 using a California representative sample in the United States. Data were taken from the California Health Interview Survey (CHIS) from 2001 to 2012. 282,931 adults were included in the analysis. During 2001–2012, the prevalence of current smoking decreased from 18.86 to 15.4 percent among adults age 18–60. As for adults age >60, the prevalence of current smoking trend decreased with variations, started from 9.66 percent in 2001, slightly increased to 9.74 percent in 2003, but then gradually decreased, falling to 8.18 percent in 2012. In 2012, there was a 14 percent reduction of daily smoking adults age 18–60 compared to 2001, while no significant reduction of daily smoking was observed for those age >60.