More than 45,000 people descended on Marvel Stadium on Saturday for the second day of the Jehovah's Witness international convention.

Thousands of Jehovah's Witnesses, many from around the world and interstate, streamed into the stadium on Saturday, when a mass baptism of more than 400 people was the highlight of the day's events.

Jehovah's Witnesses at a mass baptism at Marvel Stadium on Saturday. Credit:Paul Jeffers

Typically dressed in shorts and T-shirts, men, women and children of all ages, including one man in his 70s, took part in the full immersion baptisms, in baths dotted around the stadium's playing surface.

"We typically do the baptisms on Saturday lunchtime at our conventions," said Jehovah's Witnesses local spokesman, Mark Lewis.