California has one of the lowest smoking rates in the U.S. However, the California substance use disorder (SUD) treatment system collects no information on tobacco use. We explored smoking prevalence among persons enrolled in 20 residential SUD treatment programs, and whether persons who wanted help with quitting smoking received such help.Treatment program clients (N = 562) were surveyed about their smoking behavior and about tobacco-related services they received. Self-report smoking status was verified via expired carbon monoxide (CO) measurement. Multivariate analyses assessed whether clients who wanted help with quitting smoking received tobacco-related services (ask, advise, referral, counseling, pharmacotherapy) RESULTS: Using client self-report and expired CO, smoking prevalence in this sample was estimated at 68.9 %. Among smokers, mean cigarettes per day (CPD) was 9.7 (SD = 7.6), 58.8 % had made a quit attempt in the past year, 32.7 % were considering quitting smoking in the next 30 days, and 37.9 % wanted help with quitting. Clients who wanted help with quitting, compared to those not wanting help, were more likely to receive advice on how to quit, and tobacco-related counseling, referral, and pharmacotherapy.In this study, wanting help with quitting was associated with receiving tobacco related services. Nonetheless, fewer than half of the smokers in SUD treatment wanted help with quitting, and many who wanted help did not receive it. Given the high prevalence of smoking, and associated consequences for both general health and SUD recovery, SUD treatment systems should ensure tobacco-related assessment and intervention for all smokers.