Sent into training with Jeremy Tree, Rainbow Quest began his racing career at Newmarket Racecourse in August 1983 when he defeated twenty-nine opponents in the El Capistrano Stakes.
In the following month, he beat nineteen rivals in the Haynes, Hanson and Clark Conditions Stakes over one mile at Newbury Racecourse.
El Gran Senor took a lead in the closing stages, but Rainbow Quest cut his advantage back to half a length at the line.
As a result of irreparable complications following surgery for colic, Rainbow Quest was euthanised on 7 July 2007 at Juddmonte's Banstead Manor Stud near the village of Cheveley in East Cambridgeshire.
[4] c = colt, f = filly, g = gelding Rainbow Quest was the Leading broodmare sire in Great Britain & Ireland in 2003 and 2004.