Thoroughly Modern Millie is known to have a "higher than average" defect rate. This is mainly due to the insanely long sides. Why DiscoVision elected to master this title on 5 sides and The Blues Brothers, which runs 6 minutes shorter, on 6 sides is a mystery. Had the film been more balanced, the quality would have been better. All copies viewed have the red bumpers and begin side 1 with the full opening DiscoVision bumper.
Thoroughly Modern Millie was reissued in June 1986 by MCA Home Video (Catalog #: 17001). It spans 3 CLV sides and features a Stereo soundtrack with Digital sound.