Despite the impact of problem gambling on affected family members (AFMs), there are limited large-scale population level studies identifying the negative mental health (NMH) and positive mental health (PMH) characteristics of AFMs. Furthermore, no study has explored whether PMH characteristics are protective in the relationships between AFM status and NMH characteristics. This study involved secondary data analysis from the Third Social and Economic Impact Study of Gambling in Tasmania. Using a subsample of 1,869 adults (48.30 % male; meanage = 48.48; 4.67 % AFMs), this study aimed to explore whether: (1) AFM status is associated with NMH (depression, anxiety, panic, post-traumatic stress disorder, social anxiety, binge drinking, tobacco use, and drug use symptoms) and PMH (quality of life [QOL], personal growth/autonomy, interpersonal/social skills, coping skills) characteristics after separately controlling for sociodemographic, problem gambling severity, and other NMH characteristics; (2) PMH characteristics moderate (buffer) the relationships between AFM status and NMH characteristics; and (3) gender influences these relationships. AFM status, defined as exposure to family member gambling problems, significantly positively predicted NMH characteristics (depression, anxiety, panic, PTSD, and tobacco use symptoms) and negatively predicted QOL (physical, social) and planning coping. The strength of these relationships generally attenuated after controlling for various covariates. Gender did not moderate these relationships. Religious coping exacerbated the relationship between AFM status and panic disorder symptoms. These findings can inform the development of intervention initiatives for family members exposed to gambling problems. Future population-representative research is required using a range of affected other types, longitudinal study designs, and more comprehensive measures.