This study examined the role of significant win and psychosocial factors in the development of problem gambling (PG). Adults who gambled on pure chance games were surveyed in France and Poland. Universal risk factors for PG included male gender, younger age, lower household income, current or past debt, and more frequent gambling. The risk of PG was also higher for gambling games other than lotteries. Coping and social motives were associated with a higher risk of PG, while financial motive was associated with a lower risk. Inter-country differences were also detected. Observing a significant win by someone in the social environment was linked to a higher risk of PG for French participants only. Only the highest level of gambling spending was associated with a higher risk of PG for French participants. For Polish participants, lower levels of gambling spending were associated with a higher risk of PG.