West Java Pusdai Mosque has a very important role. Aside from being a place for congregational prayers, Pusdai Mosque is also a center for preaching and Islamic activities in West Java. Therefore, this mosque needs to create a comfortable atmosphere as a place of worship for Muslims. The comfort or solemnity of worship can be affected by the noise of the surrounding environment or the acoustics of the room. This study aims to analyze the acoustic quality of the room at Pusdai Mosque, which is influenced by several factors. This research was conducted by observing and simulating using Ecotect v5.50 software. The simulation was carried out by creating a 3D model by adding the absorption coefficient of the material and adding speakers. In addition, the research is also strengthened by a literature review of scientific articles. The simulation was carried out to determine the reverberation time and sound distribution produced by sound sources or speakers, which can indicate the acoustic quality of Pusdai Mosque. The acoustic quality of Pusdai Mosque is greatly influenced by the interior materials and the shape of the ceiling. Based on the results of the analysis, Pusdai Mosque has room acoustic defects. This is due to the large use of sound-reflecting materials and the form of ceiling, which is quite complex. This causes a lot of sound reflection to occur, causing the reverberation time to exceed the optimum limit for the frequency of 500 Hz (conversational space). This causes the speaker's voice to become an echo or hum. Therefore, Pusdai Mosque needs to improve the room acoustics to create comfort and solemnity in worship. Improvements can be achieved by adding sound-absorbing material.