People with substance-use disorders have elevated rates of tobacco use compared with the general population, yet rarely receive tobacco-dependence treatment within substance-use treatment settings (SUTS). One barrier to delivering evidence-based interventions in SUTS is providers’ misconception that treating tobacco use and non-nicotine substance use concurrently jeopardizes clients’ substance-use recovery, although research indicates that it enhances support for recovery and relapse prevention. A total of 86 treatment providers employed in SUTS (i.e., 9 Federally Qualified Health Centers, 16 Local Mental Health Authorities (LMHAs), 6 substance-use treatment programs in LMHAs, and 55 stand-alone substance-use treatment centers) in Texas, USA, answered survey questions about their (1) thoughts about treating tobacco during substance-use treatment, and (2) delivery of the 5A’s tobacco-use intervention (Ask, Advise, Assess, Assist, Arrange). Twenty-six providers and leaders were interviewed about attitudes toward tobacco-free workplace policies and tobacco dependence and the relative importance of treating tobacco (vs. other substance-use disorders) at their center. Providers who did not believe tobacco use should be addressed as soon as clients begin treatment (i.e., endorsed responses of after 1 year, it depends on the client, or never) had lower odds of Asking clients about their tobacco use (OR = 0.195), Advising clients to quit smoking (OR = 0.176), and Assessing interest in quitting smoking (OR = 0.322). Qualitative results revealed barriers including beliefs that clients need to smoke to relieve the stress of substance-use recovery, are disinterested in quitting, fears that concurrent treatment would jeopardize substance use, and limited resources; additional training and education resources was the key facilitator theme. The results demonstrate a critical need to eliminate barriers to tobacco-treatment provision for clients in SUTS through education to correct misperceptions, specialized training to equip providers with knowledge and skills, and resources to build center capacity. Integrating evidence-based smoking interventions into routine care is key to support the recovery efforts of clients in SUTS.