BACKGROUND: Encouraging and assisting smokers to quit remains a key public health goal. Government and commercial initiatives have nudged smokers towards supported cessation. We tracked long-term trends in Australian smokers' quit attempt methods across 20 years.

METHODS: Data from 11,917 smokers were collected from an annual, cross-sectional, face-to-face, random and representative population survey. The survey measured demographic characteristics, tobacco use, recent quit attempts, nicotine dependence, quit intentions, and recent methods used when attempting to quit. Quit attempt preferences were analysed over time and by smoker characteristics.

FINDINGS: Each year, more smokers attempted to quit than remained quit, with a stable trend over time. Socioeconomic disadvantage and mental health conditions are more likely among smokers, but there was no difference in quit attempts by these characteristics. Quit attempts have risen among those aged 60 years and over whereas other age groups have remained stable. Although trending downwards, unassisted quitting remained the most common method: 1998: 61% and 2017: 40%. Asking a doctor for help/advice (34%) was the most common assisted method in 2017, increasing from 18% in 1998. Methods of quitting varied by smoker characteristics, with supported methods used more often by older, more dependent, socio-economically disadvantaged smokers and those with a mental health condition.

INTERPRETATION: The relative stability of recent quit attempts, persistence in unassisted quitting, and fluctuating preferences for supported cessation methods indicate that it is important for clinicians and policy makers to continue to support quit attempts through a variety of options, tailored to smoker's needs.