Adopting healthy lifestyle behaviours is an important component of Type 2 diabetes (T2D) self-management, which can lower risks of further health complications. Monitoring lifestyle risk factors including overweight or obesity, healthy diet and physical activity behaviours, alcohol consumption, smoking and psychological distress remain important. This study examined prevalence trends in these factors and adoption of three diabetes lifestyle self-management strategies in adults (aged 40+) with T2D in New South Wales (NSW), Australia. Analyses were conducted on NSW Adult Population Health Survey data, 2004–2019 (n = 142,168), using predicted probabilities from generalised linear models, weighted to population estimates. Throughout the study period overweight or obesity prevalence remained higher amongst those with T2D (83.1% to 81.7%) compared to those without diabetes (61.0 to 61.2%); only 8.9% of those with T2D were trying to lose weight. During the study period, there were declines in the proportions of those with T2D reporting sufficient fruit consumption [63.9% to 50.1%], moderate vegetable consumption (3 serves) [49.0% to 37.7%], and achieving sufficient physical activity [40.0% to 34.0%]. There were also declines in those reporting they manage their diabetes through following a special diet [73.6% to 55.9%] and exercising most days [33.5% to 22.2%]. This study highlights potential gaps in T2D secondary prevention and suggests more targeted diabetes education services are needed to address lifestyle risks. Increased understanding of why fewer people with T2D adopt these lifestyle management strategies is needed to inform policy and practice. © 2022