Since the first major appeal in 1980, more than £840m has been raised to help children in the UK.
Pyjama parties, leg waxing and carwash karaoke were among the many fundraisers which took place across Wales on Friday to raise money for this year's event.
By 22:45 GMT, more than £2.6m had been raised in Wales.
The annual telethon started at 19:30 on BBC One with live broadcasts from Swansea.
Schools and offices across Wales took part in fundraising activities.
Pudsey the Bear even joined in for some work experience with South Wales Fire and Rescue Service crews at Barry fire station on Thursday.
The charity aims for every child in the UK to have a safe, happy and secure childhood to help them reach their potential.
BBC Wales' live broadcast of Children in Need came from Swansea University's Great Hall.
BBC Radio Wales presenter and Welsh tenor Wynne Evans hosted a night of entertainment and fundraising and was set to perform along with Baby Queens, Tenors of Rock, and Jodi Bird.
Children in Need support youngsters affected by:
Jemma Wray, national head for Wales, BBC Children in Need, said: "We are delighted to be in Swansea for this year's appeal show.
"BBC Children in Need supports a range of projects in the Swansea area that are helping to change the lives of disadvantaged children and young people.
"We are always overjoyed by the support we receive from the Welsh public and hope this year is no different!"
The BBC Children in Need charity has spent £9.2m on 159 active projects in Wales in the last year - helping 20,000 disadvantaged children.