Background:Cardiovascular diseases remain the leading cause of death worldwide. Metabolic syndrome (MetS) is the clustering of risk factors for developing the disease. Strong evidence exists for the efficacy of screening for MetS. However, the potential of novel web-based studies for MetS and online assessing of the quality of life (QOL) for these high-risk participants have not been explored.Methods:This was a web-based, cross-sectional study. Participants were recruited through online registering on the study website. Then, those who met the study criteria (waist circumference [WC] ≥90 and blood pressure [BP] ≥130/85) were contacted and invited for the clinical assessments, if they wish. Baseline measurements were MetS risk factors (weight, WC, body mass index and BP, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglycerides, and fasting blood glucose) and health-related QOL (HRQOL) that was measured using the short form-36 (SF-36).Results:There were 1436 (male: 928, female: 508) registration data on the study website. Reviewing the data, of 317 eligible participants that were invited to the study, 229 persons were responded to invitation in the screening program. The mean age of participants was 43.8 (standard deviation [SD] = 9.9) years. MetS was more frequent in male and married persons. In addition, participants with MetS had lower mean (SD) scores than participants without MetS for the following subscales of HRQOL as: role-physical (with MetS 51.1±35.2; versus without MetS 65.3 ± SD = 40.1), vitality (with MetS 65± 21; versus without MetS 75.3 ± 21.1), mental health (with MetS 49.5±30.1; versus without MetS 34.1±17.2)(P < 0.05 for all).Conclusions:People with MetS experienced lower HRQOL than without MetS. Internet as a powerful medium offers a novel setting for delivery health information. It seems that high BP and abdominal obesity are associated with lower HRQOL in the participants with MetS. A web-based prevention program could make people aware for their vulnerability to MetS and its complications.