BACKGROUND:One quarter of the world's adults have metabolic syndrome. Lifestyle modification is the first line of intervention as improvements in diet and exercise can have positive effects on the individual components of metabolic syndrome. The primary aim of this research was to evaluate the effect of an 8-week lifestyle intervention program for people with metabolic syndrome on emergency department presentations, hospital admissions, and metabolic parameters. METHODS:A retrospective case-control study of adults (n = 58, mean age 60 ± 7 years) with metabolic syndrome referred to a group lifestyle self-management intervention program between 2013 and 2015. The intervention program consisted of 8 weekly sessions of group exercise and education delivered in a community healthcare setting. The intervention group (n = 29) was compared with a group of people who declined to attend the program (n = 29). Data were collected from the time a participant was referred to the program, and all participants were followed for a minimum of 100 days. RESULTS:Participants who attended the lifestyle intervention program had significantly fewer emergency department presentations [risk ratio (RR) 0.31, 95% confidence interval (CI) 0.11 to 0.83] and potentially avoidable emergency department presentations (RR 0.06, 95% CI 0.004 to 0.097) over the follow-up period (mean 495 ± 224 days per participant). There were no differences between the groups in hospital admissions and there were insufficient data to determine changes in metabolic parameters. Lifestyle group participants increased their exercise capacity [6-min walk test mean difference (MD) 41 m, 95% CI 20 to 62, P < 0.001] and had a mild decrease in weight (MD -0.8 kg, 95% CI -1.5 to -0.2, P = 0.018) and waist circumference (MD -1.3 cm, 95% CI -2.1 to -0.6, P = 0.002) after 8 weeks. CONCLUSIONS:Implementation of a group lifestyle intervention program to improve activity and self-management skills may assist in decreasing emergency department presentations.