In the title 1:1 silver(I) 4-carb-oxy-pyridine-3-carboxyl-ate adduct with triphenyl-phosphine, [Ag(C(7)H(4)NO(4))(C(18)H(15)P)](n), the carboxyl-ate anion bridges the phosphine-coordinated Ag atoms through its N and O atoms, generating a coordination polymer forming layers in the bc plane. The Ag atom exists in a distorted tetra-hedral geometry. The H atom of the carboxyl-ate is midway between two O atoms of the two carboxyl groups, thus forming a strong intra-molecular hydrogen bond.