Background: Anxiety disorders in older people are highly prevalent, yet there is little evidence to guide targeted prevention strategies. Aims: To identify subgroups at increased risk of developing anxiety in later life. Method: Anxiety was measured with the Hospital Anxiety and Depression anxiety sub-scale in 1931 people aged 55-85 years followed over 3 years. Risk factors were identified that had a high combined attributable fraction, indicative of substantial health gains when the adverse effect of the risk factors can be contained. Results: Factors significantly associated with increased risk of developing anxiety included sub-threshold anxiety, depression, two or more chronic illnesses, poor sense of mastery, poor self-rated health and low educational level. Conclusions: The identified risk groups are small, thus providing prevention with a narrow focus, and health gains are likely to be more substantial than in groups not exposed to these risk factors. Nevertheless, more research is needed to produce evidence on target groups where prevention has optimal impacts.