The four-factor vulnerability model posits that the personality factors of hopelessness, anxiety sensitivity, impulsivity, and sensation seeking are relevant for engagement in and escalation of addictive behaviours (Conrod et al., 2000a). While initially validated for substance misuse, this model has not yet been utilized in studying behavioural addictions such as disordered gambling. We investigated the relationship between the four-factor personality variables and gambling frequency/problems using the Substance Use Risk Profile Scale (SURPS; Woicik, Stewart, Pihl, & Conrod, 2009), the Gambling Timeline Followback (G-TLFB; Weinstock, Whelan, & Meyers, 2004), and the Problem Gambling Severity Index (PGSI; Ferris & Wynne, 2001), respectively. Data were collected from a university sample (Study 1; N = 255) and a mixed sample of university and community recruited adult gamblers (Study 2; N = 198). In cross-sectional regression analyses, impulsivity predicted gambling frequency and problems across samples; hopelessness predicted concurrent gambling problems in the mixed sample. Study 2 included a six-month follow-up assessment, allowing for longitudinal analyses. Hopelessness predicted escalation in gambling problems, and impulsivity predicted escalation in gambling frequency. Overall, our results demonstrate the utility of the four-factor vulnerability model as a tool for gambling research while identifying impulsivity and hopelessness as personality risk factors for frequent and problematic gambling.