To compare two self-help smoking cessation booklets distributed to callers to a Quitline telephone service in Queensland (Australia). Callers were randomised to receive either a structured 14-day quit programme (Time to quit) or another booklet and described four broad stages of quitting (Can quit). Approximately one month later, these callers were interviewed by telephone. Self-reported smoking status at one month and recent quit attempts together with process measures. Altogether, 521 callers (78.3%) were interviewed. They were heavier smokers when compared with all Queensland smokers: on average they had smoked for more than 15 years, smoked nearly 25 cigarettes per day, and almost two-thirds had attempted to quit smoking in the past year. In each group, significant proportions either did not begin to use the booklet (50.5-56.0%), or did not complete its use (77.4-82.3%). There were no differences in the self-reported quit rates at one month (17.0% vs 16.1%; p = 0.93). In an ordinal regression modelling procedure involving age, sex, number of recent quit attempts, number of cigarettes smoked per day, smoking status of partner, number of five closest friends who smoke, education, and booklet received, only the number of cigarettes smoked per day was significantly related to smoking status at one month. Callers to telephone Quit-line services are typically heavier smokers than the general smoking population, and simple strategies, such as self-help booklets, appear to achieve relatively high success. Nevertheless, there is potential to improve the effectiveness of these materials by making a range of materials available and encouraging callers to make a serious attempt to quit smoking.