Tobacco control programs, smoking bans, and taxes have been utilized to reduce cigarette smoking in the United States. Found in all tobacco products, nicotine is highly addictive, and many anti-smoking laws can be subverted with other tobacco products. Additionally, many researchers are promoting the use of potentially reduced-exposure products (PREPs) for harm reduction to cigarette smokers. The purpose of this dissertation was to study the use of alternative tobacco products in California, including smokeless tobacco (both traditional products and PREPs), cigars, and hookah. Some data are drawn from the California Tobacco Surveys (CTS), which are large, population-based random-digit-dial telephone surveys that collect representative statewide data on tobacco-related behaviors. Analysis of the 1990-2008 CTS was conducted to estimate prevalence and trends of cigar, smokeless tobacco, and hookah use in California adults as well as PREP use among current adult smokers. The remaining data were from a cross-sectional survey of high school students conducted to estimate hookah-use patterns and risk factors among this highly susceptible population. From the 2008 CTS, male cigar current-use was 7.8% and female ever-use was 7.0%, the highest recorded levels since the inception of the CTS in 1990. Ever-use of hookah was 11.2% among males and 2.8% among females. Hookah use has increased by more than 40% since 2005 and is highly prevalent among young adults. Among California smokers, hypothetical cigarette replacement receptiveness was 10.3% for health reasons and 15.2% for convenience reasons. Use of actual PREPs was also low (Snus, 2.2%; Ariva, 1.5%; other PREPs, 4.1%). From the high school survey, hookah use (ever-use, 26.1%; previous month, 10.9%; current, 10.3%) was higher than adult use from the CTS. Subjects believed hookah is more socially acceptable and safer than other tobacco products. Users were more likely than non-users to report a hookah lounge in their community. Current users were more likely than former users to have recently smoked a cigarette, report a hookah lounge in their community, and believe hookah is more socially acceptable than cigarettes. The use of alternative tobacco products is not decreasing in California. Specifically, the use of hookah is concerning, as both adolescents and young adults are smoking hookah at a higher rate than other products. Hookah-specific interventions and the legality of 'hookah lounges' represent opportunities for immediate action.