The present invention provides a non-cyanide electroless gold plating solution free from a cyanide compound, comprising, as a completing agent of gold, a compound represented by the formula shown below or a salt thereof: X--(CH.sub.2).sub.n--SH wherein n is 2 or 3 and X is SO.sub.3H or NH.sub.2, and having a pH value of 7 or less. The invention also provides a process for electroless gold plating using the non-cyanide electroless gold plating solution.