A randomized telephone survey of Sydney residents aged 16-50 was conducted in 1988 (n = 651) and repeated in 1989 (n = 701) to assess changes in AIDS-related knowledge and attitudes and opinions about AIDS policies. The mean number of correct answers to 21 questions about AIDS was 18.6 (1988) and 18.1 (1989). Almost all respondents gave correct answers to fundamental questions about AIDS transmission and prevention. No statistically significant changes in AIDS knowledge were found between the two survey periods. There was widespread anxiety about AIDS: just over half the population was personally afraid of getting AIDS, 80 per cent had considered being tested for human immunodeficiency virus and over half supported 'compulsory testing' for all the population. Mass media messages about AIDS were almost universally recalled, with the Grim Reaper and news stories centring on particular individuals ranking highest. AIDS policy makers in public education should consider the wisdom of continuing to target messages to low-risk populations. These messages have raised fundamental knowledge about AIDS but may be unintentionally causing social divisiveness and widespread unnecessary anxiety.