It is not uncommon for actors to double and triple in roles while appearing in the omnibus plays of Neil Simon. Plaza Suite was the first film version of a Simon play to carry over the multiple-role device to the screen. Walter Matthau appears in all three one-act playlets comprising Plaza Suite, with a different leading lady in each.
First we see Matthau as the husband of Maureen Stapleton, nostalgically returning to the same hotel suite where they'd spent their honeymoon 24 years earlier. Times have changed, however, and the twosome spend more timing sniping at one another than pitching woo.
The second vignette casts Matthau as an effusive movie producer (lavish toupee and all) who hopes to seduce his old sweetheart Barbara Harris. The third and best sequence finds Matthau and Lee Grant playing the parents of a bride who steadfastly refuses to leave her locked room to attend her own wedding.