A quarter of the problem gambling group reported a suicide attempt in the past year, and they were about 18 times more likely to report a suicide attempt than other students. [...] Youth Gambling Prevalence in Ontario Little information on the prevalence of gambling and gambling problems in Ontario adolescents before the 1990s is available. [...] The 12-item version of the SOGS-RA was used in the OSDUHS between 1999 and 2003. [...] The large sample of the OSDUHS also permits an examination of more uncommon behaviours in the problem gambling population. [...] The main purposes of the report are as follows: a) to describe the prevalence of gambling behaviour among Ontario students in grades 7 to12; b) to describe the prevalence of gambling problems among Ontario students in grades 7 to12; and c) among students identified with a gambling problem, to describe co-occurring or comorbid problems that they may be experiencing.