Fish In Church begins on Saturday in Lyde just north of Hereford where the parish church is dedicated to St. Peter the fisherman.
The event will last all week and PCC secretary Bob Calver, said: "We've got live fish in the font and some beautiful tropical fish on the altar.
"There'll also be some robotic fish and a few other surprises.
"To get an idea just think flower festival but replace the flowers with fish."
There will even be fish-themed activities including a performance of popular organ music and a Japanese flower arranging demonstration.
Mr Calver added: "We're having a film show, too, so we're screening 'Salmon Fishing In The Yemen' on the evening of the 25th."
He said the live fish have been supplied by Kenchester Water Gardens which is opposite the church: "the Owner Malcolm Edwards was Christened at St. Peter's and loved the idea of putting fish in the font."
The idea behind the fish-themed stunt is to bring more visitors and local people to the church.
Everyone will have the opportunity to fill in special fish-stamped prayer cards and put them in a net.
The prayers will them be offered during the final service on Sunday 28th marking the feast of St. Peter.
