Survey results revealed that nearly 80 percent of respondents reported past year or current alcohol use, up from 72.3 percent in 1994. Past year drinking was more frequent among males (82 percent) than females (76.8 percent), as was monthly heavy drinking (33 percent of males and 17 percent of females). Less than 10 percent of females and 25 percent of males were identified as hazardous drinkers. However, nearly 1 in 10 current drinkers reported that their alcohol use had caused harm to themselves or others during the previous year. Like alcohol use, both past year and lifetime cannabis use increased among Canadians during 2004, with 14.1 percent of respondents reporting past-year use and 44.5 percent reporting lifetime use. Males were more likely than females to report past-year cannabis use (50.1 percent and 39.2 percent, respectively). The majority of past-year cannabis users (47.2 percent) were aged 18 to 19 years. Public attitudes were divided about whether the possession of small amounts of cannabis for personal use should be illegal: 46.1 percent believed it should be illegal while 49.8 percent believed it should be legal. While most Canadians restrict their illicit drug use to cannabis, the other substances reportedly used by respondents during their lifetime included hallucinogens (11.4 percent), cocaine (10.6 percent), speed (6.4 percent), and ecstasy (4.1 percent). Of those reporting lifetime use of other illicit drugs, 21.1 percent were male and 12.2 percent were female. Almost half (45.7 percent) of lifetime users of other illicit drugs reported one or more types of harms resulting from their illicit drug use. Previous research on drug abuse among Canadian Federal prisoners is also presented, which indicates that almost 25 percent of Federal prisoners committed their crimes in order to obtain alcohol and/or drugs. 7 tables, 17 notes