Online pharmacies are increasingly common, and some of them have been reported to inappropriately supply prescription-only medicines. Dextropropoxyphene-containing compounds are addictive and frequently implicated in fatalities occurring in the United Kingdom. We aimed here at assessing the online availability of dextropropoxyphene for purchase over a time-span of 2 years (September 2003-August 2005). A Google search was run in September 2003 using different sets of keywords and the first 100 links identified were thoroughly assessed. In March 2005, the same e-pharmacies websites identified at baseline were accessed again and a Google search using the same sets of keywords previously used was run as well. Furthermore, a specialized search with Froogle was run both in March and August 2005. Although an illegal practice in most countries, a number of websites willing to sell the compound internationally were identified at the time of the baseline search. In March 2005, the Google search for vending websites identified 361,000 links, compared with 40,000 18 months before. Only half of dextropropoxyphene vending e-pharmacies were still active by March 2005 but, at that point in time, access to Froogle apparently facilitated the task of online dextropropoxyphene purchase. By August 2005, however, the same Froogle search identified only one link aimed at online dextropropoxyphene shopping. In the United Kingdom, dextropropoxyphene-related products will be withdrawn later this year but this may have only limited impact on the availability of the compound. The emergence of Internet as an unregulated source of controlled substances is an important development that may have significant public health implications. This issue needs to be dealt with at both international and national level.