Christ on The Cross, which was painted by Mr Howson in 1964, was one of the highlights at the McTear's Scottish Contemporary Art Auction yesterday.
The oil painting, which measures 13ins by 9ins, was exhibited at Peter Howson: A Retrospective, in the McLellan Galleries in Glasgow from July to September 1993.
Half the proceeds from the painting's sale will be donated to Marie Curie Cancer Care.
Brian Clements, managing director at McTear's Auctioneers, said: "Peter Howson is one of Scotland's most prominent artists so there was understandably a lot of interest in his first ever oil painting.
"Christ on the Cross is an extremely emotive piece and to think that it was created by a six-year-old child is simply extraordinary."