Phuket Governor Tri Augkaradacha was on the scene as fireman brought the blaze under control in about 40 minutes.
The fire, according to first reports, broke out on the fourth floor, in Cinema 6, which was empty with no audience at the time, and spread to Cinema 5, which was under renovation.
Somebody smelled the smoke and raised the alarm, sparking an evacuation of Cinemas 1, 2, 3 and 4.
The cinema complex is in the same block as Ocean deaprtment store, opposite Robinson in what was once the retail heart of Phuket.
A cinema spokesperson said tonight that it was too early to suggest a figure on the damage done, or when the multiplex might reopen.
A Thai movie, 'Valentine,' was screening at some of the cinemas.