The dimensional stability of a range of elastomeric impression materials has been assessed to study the effect of storage in sterilizing solutions. Experiments were carried out on audiological silicones of condensation and addition types. Further, a number of dental-based materials comprising a polysulphide, a polyether, a condensation and an addition silicone, were also investigated for comparison. The results indicate that the addition silicones had the greatest dimensional stability over a range of storage conditions, which included aqueous glutaraldehyde and hypochlorite solutions.