The objective of this study was to determine whether awareness of hepatitis B virus (HBV) serostatus was discordant with metabolic syndrome (MetS) among people with chronic HBV infection. We conducted a community-based study in four Taiwanese districts. A total of 3493 adult participants were recruited. Participants who were hepatitis B surface antigen (HBsAg) seropositive and had self-reported HBV infection were considered aware of hepatitis B (aHB); those who denied a history of HBV infection were considered unaware of hepatitis B (uaHB). Among the 454 participants who were HBsAg seropositive, 275 (60.6%) were aHB and 179 (39.3%) were uaHB. Hypertriglyceridemia showed significant inverse association with HBsAg seropositive, especially among those who were aHB. Insulin resistance was significantly, positively associated with HBsAg seropositive, especially among participants who were uaHB. Those who were uaHB had a higher risk of central obesity, hyperglycemia, insulin resistance, and MetS than those who were aHB (odds ratio = 2.33, 1.64, 2.15, 1.85, respectively, all p < 0.05). The association among the prevalence of MetS, its individual components and HBsAg seropositivity varies according to awareness of HBV infection. It is important to recognize an individual's risk for MetS, especially who were unaware of HBV infection.