GO:0060585

Any process that increases the rate, frequency or extent of prostaglandin-endoperoxide synthase activity. Prostaglandin-endoperoxide synthase activity is the catalysis of the reaction: arachidonate + donor-H2 + 2 O2 = prostaglandin H2 + acceptor + H2O. [GOC:BHF, GOC:dph, GOC:tb]