The　cobalt(III)　violurato　complex　([Co(C4H2N　3O4)3]-6H2O,　Mr　=　635.28)　has　been　prepared　and　structurally　characterized.　The　crystal　is　of　monoclinic,　space　group　P21/n　with　a　=　10.176(1),　b　=　11.8010(9),　c　=　19.706(2)　Å,　β　=　97.382(3)°,　V=　2346.9(4)　Å3,　Z　=　4,　Dc=　1.798　g/cm3,　F(000)　=　1296,　μ=　0.839　mm　-1,　R　=　0.0482　and　wR　=　0.1357.　The　Co　atom　in　the　title　compound　is　six-　coordinated　by　three　carbonyl　O　atoms　and　three　oximido　N　atoms　of　three　violurato　ligands,　forming　an　octahedral　coordination　geometry.　The　neighboring　molecules　are　connected　together　by　hydrogen　bonds　of　N-H⋯O,　O-H⋯O　and　O-H⋯N,　forming　an　extended　three-dimensional　supra-　molecular　architecture.