OBJECTIVES: To determine the number of pharmacoeconomic messages in prescription drug advertisements in major Finnish medical journals and whether their number has increased over time. Additionally, to determine what kinds of claims these advertisements include, whether supporting evidence is provided, whether generic substitution has had an effect on the number and which drugs were most frequently promoted. METHODS: Prescription drug advertisements in three Finnish medical journals were examined. The first issue published in January, July and October in 1990-2003 was examined. All prescription drug advertisements in the journals were counted and the ones with economic messages were copied and analyzed with a structured data collection form. RESULTS: There were 2175 advertisements in the sample of 126 journals, of which 455 included economic and 294 quality of life -messages. The number of economic content ads had increased from 19 in 1990 to 54 in 2003 (Pearson 0,75). The most frequently used economic claims were cheap or economical and references to reimbursement or price. The most often used quality of life claims were quality of life, easy, good or better life or day or statements describing life (e.g. balanced). Evidence for economic claims was found in 23% of the advertisements and more than half of them referred to the price list. Evidence for quality of life claims was found in 20% of the ads and most of them referred to scientific studies. Generic drugs were advertised most in 2001-2002, just before the generic substitution was initiated in Finland. Economic messages were most frequently used for antidepressants, ACE inhibitors and anti-inflammatory drugs. CONCLUSIONS: 1) The number of economic content advertisements has increased over time in Finnish medical journals. 2) Evidence for the claims were found in approximately 20% of the advertisements.