The development of evidence-based ("collaborative care") mental health services in primary care for young people with anxiety, depression and alcohol or other substance misuse is a major challenge. Data from two clinical audits of selected Australian general practices (1998-1999 and 2000-2002) were analysed to explore actual experiences of care among people aged 16-25 years. Syndromal (1998-1999: 31.0% [n = 1849/5957]; 2000-2002: 37.8% [n = 148/392]) and subsyndromal (1998-1999: 27.4% [n = 1635/5957]; 2000-2002: 29.1% [114/392]) mental disorders are very common among young people presenting to general practitioners. However, a mental health diagnosis (1998-1999: 42.6% [n = 740/1736]; 2000-2002: 52.0% [n = 77/148]) or provision of formal treatment (1998-1999: 36.1% [n = 600/1661]; 2000-2002: 51.7% [n = 74/143]) occurs in only about half of the patients with syndromal conditions. While some active treatment was received by 19.4% (1998-1999 [n = 1018/5236]) and 35.9% (2000-2002 [n = 133/370]) of the young people, respectively, the most commonly reported interventions were non-pharmacological alone (1998-1999: 13.1% [n = 687/5236]; 2000-2002: 22.4% [n = 83/370]) or non-pharmacological and pharmacological combinations (1998-1999: 4.1% [n = 214/5236]; 2000-2002: 10.3% [n = 38/370]). Only rarely is pharmacological treatment alone provided (1998-1999: 2.2% [n = 117/5236]; 2000-2002: 3.2% [n = 12/370]). New systems of primary care for young people need to be based on proven collaborative care models and encourage presentations for care, increase detection rates, and promote access to information and effective e-health services. Improved access to specific psychological treatments should remain a priority.