It has been traditional either to cast invested wax patterns immediately after the investment has set or to store the invested patterns in a humidor for casting later. This study compared the fit of MOD inlays to parent dies after casting immediately following set of the investment, after casting 1 hour following the setting of the investment in air, storage in a humidor for 7 days, and after storage in air for 7 days. The only significant differences in fit were in the group stored in a humidor, and then only at the axiogingival junctions.