INTRODUCTION: The percentage of presentations at congresses that are later published is a measure of the scientific impact of these meetings. Our objective was to investigate how many studies presented in four Spanish national conferences (2000-2003) had been published in Spanish and international biomedical and dermatology journals, with or without an impact factor. MATERIAL AND METHODS: A search for publications in international indexed journals (using PubMed) or publications in unindexed Spanish journals (using Dermabase/Indice Médico Español) was undertaken by the name of first author, the first and last author, and the key words of the article. RESULTS: Of a total of 1,471 scientific presentations, only 200 (13.5 %) were published (118 in Spanish journals and 82 in international ones); that is, 1,271 studies (86.5 %) were not published either in a Spanish or an international journal. CONCLUSIONS: We found a low impact in terms of the publication rate for abstracts presented in 4 consecutive Spanish National Dermatology and Venereology Congresses compared to the rate of publication for other dermatology meetings such as the British Association of Dermatologists Annual Meeting.