More than 70 people died when a park full of families was attacked on Easter Sunday.
A splinter group of Pakistan Taliban took responsibility for the attack and said that it was targeting Christians celebrating the religious festival.
The Clifton Diocese has prepared a special service in both Urdu and English to remember all of those that died and that were injured and to pray for persecuted Christians in the Middle East.
Bishop Declan will preside at the Mass on Saturday at St Nicholas of Tolentino Church to stand in solidarity with the Pakistan Christian community both in Pakistan and in Bristol.
Bristol's Lord Mayor, Councillor Clare Campion-Smith will attend.
The diocese said: "This is certainly not the first such atrocity - last year 100 homes of Christians were burnt down in one part of Lahore, and churches have been bombed.
"Here at St Nicholas, because of our ministry to our asylum and refugee brothers and sisters we know well the suffering of Christians in Pakistan.
"We pray that the authorities in Pakistan will act decisively to guarantee religious freedom and to bring all forms of religious persecution of minorities to an end."
Bishop Declan Lang also wrote to Archbishop of Karachi and President of the Pakistan Catholic Bishops' Conference, Joseph F. S. Coutts and expressed the horror the world felt following the bombing.
