Smoking-cessation campaigns and services use printed self-help materials as a major medium for assisting smokers to quit. Such materials are associated with abstinence rates of up to 20% at 12-month follow-ups. Adherence to the specific content of self-instructional programs can be poor, but higher levels of reported adherence may be associated with a greater likelihood of cessation. Personalized cessation materials do not enhance cessation rates, but social support and minimal levels of personal contact do. Research is needed to identify which specific components of these programs are effective, how adherence may be promoted and how materials may be used in conjunction with other interventions--particularly cost-effective forms of counselling and social support.