This article shows our recent room acoustic study of the baroque theatre in Litomyšl. Preseted work is performed in the framework of a lager project that investigates acoustical properties in baroque theatres with an intention to compare originally preserved theatres with those which have been renovated. Until now, research has been done on theatres in Český Krumlov (Czech Republic) and the Drottningholm (Sweden). The theatre in Litomyšl is the third one. The acoustic simulation of the Litomyšl castle theatre has been performed in Odeon software. The model was calibrated according to the measurements of reverberation time in situ on 11 microphone positions. The results of simulation and measurement are shown in octave bands in the frequency range of 125 - 4000 Hz on 11 receiver positions.