Two assessment measures, the South Oaks Gambling Screen (SOGS), and the Problem Gambling Severity Index (PGSI), were administered to 1,979 participants (53% males, mean age 44.81 years). Results from exploratory and confirmatory factor analyses showed the presence of one single dimension underlying the SOGS and PGSI items. The 2 scales showed high levels of reliability. SOGS and PGSI results were highly correlated and showed positive and significant correlations with measures of gambling behaviour. Probable pathological gamblers identified by SOGS represented 2.05% (95% confidence interval [CI] [1.17, 2.93]) of the adult Italian population, and problem gamblers identified by PGSI represented 2.17% (95% CI [1.26, 3.07]) of the population. A more conservative estimate of the prevalence of problem gambling in Italy, corresponding to 1.01% (95% CI [0.39, 1.63]) of the adult population, was identified by considering only those participants for whom SOGS and PGSI were in perfect agreement concerning risk categories.