Purpose:The objective of this cross-sectional study was to describe corresponding procedures for irreversible hydrocolloid and silicone impressions taught and used in European Union dental schools. Materials and Methods:A self-administered questionnaire requesting information about rinsing and disinfection methods was sent to each of the 373 heads of prosthodontic, pedodontic, and orthodontic departments in the 131 European Union dental schools. Response rate was 94%. Statistical analysis included chi-square or Fisher exact tests, and ANOVA or Kruskall-Wallis tests. Results:Of the responding departments, 92% systematically rinsed their impressions. Fifteen percent of the departments, mostly orthodontics, never disinfected irreversible hydrocolloid impressions, and 11% never disinfected silicone impressions. The immersion method was used by 65% for irreversible hydrocolloid impressions (73% for silicone), with a disinfection time of 10.3 ± 6.3 minutes (11.8 ± 7.4 for silicone). The disinfected impressions were not rinsed by 16% for irreversible hydrocolloid and 14% for silicone. Most departments used brand-name products. Conclusion:The same disinfection procedure for both irreversible hydrocolloid and silicone impressions was used by 78% of departments. There was great diversity, however, between departments in the procedure used for each impression material. Int J Prosthodont 2004;17:165–171.