The survey involved a national sample of approximately 5,800 people 13-45 years old. They were interviewed about their alcohol, tobacco, cannabis, and other illicit drug use. Regarding cannabis, they were asked about the prevalence of use, manner of procurement, the frequency of purchases, and the weights purchased. Since the cannabis purchases of the sample were theoretically representative of the cannabis purchases of the wider population, the data collected in the survey were used to estimate the dollar amount spent on cannabis by the population. Forty-nine percent of the sample had tried cannabis at least once in their lives, and 19 percent had used it in the last year. Of this 19 percent, 84 percent received at least some of their cannabis "free," with 20 percent receiving "most" and 42 percent "all" of their cannabis free. Only 8 percent grew any of the cannabis they used, with only 1 percent growing "most" and 1 percent "all" of their cannabis. Thirty-eight percent bought at least some of their cannabis, with 13 percent buying "most" and 8 percent "all" of their cannabis. The dollar value of the illicit market for cannabis in New Zealand in 2001 was estimated to be $190 million in New Zealand dollars. The bottom 50 percent of buyers spent a median amount of $100 a year on cannabis (about $2 a week). The next 25 percent of buyers spent a median amount of $750 a year. The top 10 percent of cannabis buyers spent from $3,200 to $55,200 on cannabis in the last year, with some purchasing cannabis to sell. 4 tables and 18 references