This study was conducted in D.A.V( C ) Dental College Yamunanagar to find the most suitable immersion disinfectant which causes least dimensional changes and preserves the impressions property of reproducibility. Immersion of four randomly selected irreversible hydrocolloid was done for specified period of time in three disinfectants - Glutaraldehyde, Povidone-Iodine and Sodium hypochlorite. Reproducibility was evaluated by determining the extent of reproduction of 25, 50 & 75 micronmetre width lines as per A.D.A Specifications.

Key words: Irreversible Hydrocolloid impression, Disinfectant, Dimensional stability, Reproducibility.