The Christian Legal Centre (CLC) said the venue proposed for Merthyr Tydfil would have been too close to a church and had urged planning officials to consider how it might impact "future development in the area".
Chief executive Andrea Williams said: "We are delighted with yesterday's result and thank God for this.
"It is so important for people to take a stand against these sorts of premises."
Proposals for a sex entertainment venue (SEV) in the rural Welsh town, which is close to the Brecon Beacons National Park, were unanimously rejected by a planning committee at the county borough council.
Warning how the plans might have affected local people, the committee said: "The applicant was not able to provide evidence and was therefore unable to demonstrate that the granting of a SEV of this type would not lead to the locality becoming a no go area for families, church goers, concert goers and women generally."
The CLC said it was supporting a number of people who opposed to plans and that a number of objectors have now contacted the council suggesting they work with the authority to prepare on policy on sex entertainment venues.