ObjectiveThis study examined the effects of an Internet-based Best Exerciser Super Trainer (BEST) program on cardio-metabolic risks and stress among workers with metabolic syndrome. MethodsThis study utilized a non-randomized, pretest, and posttest, controlled design with a convenience sample of 48 Korean male workers. The workers in the BEST group participated in a 16-week Internet-based program: 150min of regular physical activity per week, 200- to 300-kcal reduced daily diet for weight control, one-on-one counseling, and mobile phone text messages. Workers in the Education group received text messages and an educational booklet. ResultsThere were significant group by time interactions in cardio-metabolic risks: body weight (p=.022), visceral fat mass (p=.033), and waist circumference (p=.037). There was no group by time interaction in stress (p>.05); however, the BEST group showed a significantly greater reduction in health-related stress than those in the Education group (p=.025). ConclusionThis study yielded evidence of the beneficial impact of the Internet-based BEST program for workers with metabolic syndrome on selected cardio-metabolic risks and health-related stress. Practice implicationsInternet-based one-on-one counseling and mobile phone text messages can assist individuals with targeted lifestyle modifications for metabolic syndrome.