Al-Mannar Mosque is the oldest mosque in South Bengkulu. This mosque became the first Islamic broadcasting institution there. As the oldest mosque, it certainly has permanent worshipers and fanatics to carry out worship in that place. But the phenomenon that is happening at this time, the Al-Mannar mosque is empty of worshipers. This is certainly quite surprising because previously the oldest mosque had so many worshipers. Some previous studies only explain the efforts or steps in prosperity of the mosque or efforts to increase the interest of prayer in congregation. Research has not looked at the factors underlying the low interest of the community prayer as a source of problems. This type of research is qualitative research, with data collection tools such as interviews, observation and documentation. The data analysis with inductive techniques. The results of the study stated that there are several factors that cause the low community to carry out congregational prayers, including; the location of the al-Mannar mosque is less strategic, there are also many residents who are busy working, there are also residents who often go out of the area, many residents move their dwellings, there are also residents going out to catch fish leaving before dawn to return home at noon, busy repairing fishing gear and checking the boat if there is a shortage, the women are busy selling and salting fish, and also many new mosques have been erected.