The results of a single-crystal structure solution and refinement for silver oxalate are reported. Possible anion-anion, cation-cation and anion-cation interactions in the crystal and their role in the solid-state decomposition are discussed on the basis of (i) a detailed analysis of the Ag2C2O4 crystal structure, (ii) a statistical analysis of data from Cambridge Structural Database and (iii) ab initio calculations. The role of interstitial silver cations in the decomposition of silver oxalate is also considered from a structural point of view.