This study evaluated the quality of gypsum casts recovered from disinfected irreversible hydrocolloid impressions. Four disinfectants were evaluated: 0.525% sodium hypochlorite, Alcide LD, Iodofive, and OMC II. Water served as the control. Specimens were evaluated for roughness, surface detail, and dimensional stability. Impressions disinfected with NaOCI or Alcide produced gypsum casts with physical properties that were generally equal or superior to casts from impressions rinsed with water. OMC II and Iodofive generally produced casts inferior to the controls.