Adam Legzdins, David Davis, Michael Morrison and Ryan Shotton met and chatted to the youngsters and their parents at the Hospital in Bordesley Green.
They delivered Blues goodie bags to the delighted kids.
And a £1,000 cheque was handed over to the Rainbow Trust, a charity which raises money for the department.
The visit and donation was part of the Club's annual Christmas charity initiative. Blues players, including the Under-23s, have donated money to both the Children's Unit and St Basils, the city charity for the homeless that provides support and accommodation.
The Club's Under-23s, led by Richard Beale and Paul Robinson and Club Chaplain Kirk McAtear, visited Edmonds Court Foyer in Small Heath to aid the St Basils Christmas Shoebox appeal and learn more about the facilities and work done there.
Last week, Paul Caddis gave the Club's backing to the Birmingham Children Hospital's Star Appeal by switching on the Hospital's Christmas Lights alongside Aston Villa's Ross McCormack.