Introduction: Noise pollution in churches is one of the health challenges facing developing nations of the world. Both Pastors/Reverends are exposed to different sound levels during church services, many of which can last for hours. According to the Nigerian National Environmental standard and regulation Act 2007, the maximum permissible noise level in worship centers should not exceed 75 dB and Nigeria being the highest church proliferation in the world makes it imperative to carry out this research. Aim: the aim of this study is the measure the equivalent noise levels with their corresponding frequency levels at varying distances from the source and quantify the noise pollution levels in churches and mosques in Port Harcourt. Method: a total of 11 Pentecostal churches, 5 orthodox churches and 3 central mosques were randomly selected. This study was carried out between July and August, 2017. Sound pressure level meter was used to measure the sound levels under the weighted range in churches on Sundays between the hours of 7.30 to 12.0 pm and on Fridays in mosques between the hours of 1.30 to 3.00pm afternoon session and evening at 6.00pm. Data obtained was analyzed using ms-excel. Result: Average indoor and outdoor equivalent noise level in pentecostal churches are 95.1 dB(A) and 79.5 dB(A) respectively while that for orthodox churches are 93.6 dB(A) and 77.9 dB(A) respectively. The average indoor and outdoor equivalent noise levels in mosques are 72.1 and 100.6 dB(A). The frequency of the noise ranges from 310.75 to 785.30 Hz in Pentecostal, 482.60 to 749.02 Hz in Orthodox churches and 438.63 to 620.36 Hz in mosques. The highest noise pollution level in churches and mosques recorded are 121.18, 119.38 and 123.48 dB for pentecostal, orthodox and mosques respectively. Conclusion: all the noise pollution levels recorded in the churches and mosques are higher than the safe permissible limits of sound of 75 dB thus making it unhealthy, unsafe for the worshippers. Therefore there is need for implementation of the noise regulation laws in churches in Nigeria in order to reduce the risk of hearing loss.