When a person decides to be baptised they will normally have a period of preparation, during which the church (usually in the person of the minister) will help them understand more about the Christian faith and the meaning of baptism. This usually takes place in the weeks before baptism.

A baptism in a Baptist church is nearly always by full immersion. A Baptist church often has a baptismal pool at the front of the church that is usually hidden under the floor, with steps going down into it. Before the baptismal service, the pool is uncovered and is filled with warm water. Churches that do not have a baptismal pool may hire an inflatable birthing pool or use a local swimming pool, or even use a river or the sea if close by.

At the service itself, any being baptised will often give a testimony to the congregation on how they became a Christian and why they have chosen to be baptised. Then, immediately before baptism, they will be asked basic questions of commitment, including an acknowledgement of Jesus as Lord and Saviour.

A minister normally baptises. He or she will hold the person being baptised, placing one hand on their back and the other on their chest. They will then say the words, 'I baptise you in the name of the Father, of the Son, and of the Holy Spirit', and plunge the person being baptised backwards so that they are fully immersed in the water, before raising them back up to standing position. They then leave the water.

The person baptised will often be welcomed into church membership at communion in the same service or at the next opportunity.