Radioactive solution of ^110mAg was standardized using the 4pb-g coincidence method by efficiency extrapolation and using a calibrated high-pressure gamma ion chamber. This radionuclide is a b-g emitter with a very complex decay scheme. The activity concentrations obtained by the coincidence method and secondary method on reference date of May 15, 2005 are 208.28(0.96) kBq/g and 209.04(2.72) kBq/g respectively and are in good agreement within the quoted uncertainty limits. The results have also been confirmed by participating in the International Reference System (SIR) of BIPM. Detailed uncertainty budget for both the methods are also included.