Why people smoke despite the health risks is an important public health question. Equally important is why and how some people resist smoking in spite of circumstances that clearly place them at high risk of becoming smokers. This study used in-depth interviews to explore the narratives of 12 people diagnosed with mental illness, who had made conscious decisions not to smoke. This was despite most of them growing up in smoking families or being from population groups at high risk of smoking. A qualitative grounded theory methodology was used to analyse common themes around protective behaviours and attitudes within a model of resilience. Themes included strong negative reactions to smoking as children which have persisted into adulthood, strong lasting associations with smoking, a clear sense of 'self' separate from peers from an early age (internal resilience) and developing a range of coping strategies and external supports not related to smoking (external resilience). Understanding resilience holds potential lessons for health promotion and primary health care professionals supporting the prevention of smoking uptake and supporting smoking cessation by at risk groups.