The objective of this study was to determine the effectiveness of a statewide campaign aimed at increasing chlamydia awareness and testing among younger people. In November 2002, a narrowcast media campaign targeting men and women aged 16-29 years was launched in Victoria, Australia. This was expanded in June 2003. Data on chlamydia testing via Medicare and chlamydia notifications, before and after the campaign, were compared to determine possible effects of the campaign on population rates of chlamydia testing and detection. During the campaign, chlamydia testing rates increased significantly for both women (P=0.04) and men (P=0.04), while testing rates before and after the campaign remained relatively stable. Although testing rates increased, only 4.3% of Victorian women and 1.9% of men aged 16-30 were tested through Medicare in 2003. The increase in chlamydia testing over the study period was closely paralleled by an increase in notification rates for chlamydia, with strong correlations between the two (r=0.97, P<0.001). In conclusion, an estimated minimum of A$70 was spent on the campaign for each additional chlamydia test performed. Testing within the framework of a national chlamydia screening programme may be a more cost-effective way of increasing chlamydia testing.