BACKGROUND: Physicians play an increasing role in tobacco dependence treatment as more prescription medications and community resources are developed. Beliefs about effectiveness can influence physicians' recommendations regarding treatment, so it is critical that these beliefs are evidence-based. OBJECTIVE: Describe physicians' beliefs regarding effectiveness of tobacco treatments. DESIGN: Self-reported, cross-sectional, mailed survey. PARTICIPANTS: 336 primary care physicians in New Jersey (60.3% response). MEASUREMENTS: Demographics, previous tobacco dependence training, awareness of guidelines, and perceived effectiveness of treatments. RESULTS: Physicians believed combination medications and bupropion to be the most effective (89 and 88% reported somewhat or very effective, respectively) and nicotine nasal spray least effective (50%). For nonpharmacologic treatments, physicians believed behavioral counseling (69%) and programs including group treatment (67%) were most effective, whereas telephone counseling (25%) and internet-based treatment (23%) were the least. Female and non-U.S.-trained physicians generally believed treatments to be more effective. CONCLUSIONS: Physicians in this sample believed that most cessation medications available and behavioral and group-based counseling are effective, which is supported by current evidence in the field. Low perceived effectiveness of telephone and internet treatments could hinder their utilization. Perceived effectiveness may affect physician recommendations. Therefore, training efforts to influence these beliefs warrant further attention.