Trans-bis(ethanolamine)bis(saccharinato)mercury(II), [Hg(ea)(2)(sac)(2)], where ea and sac denote the ethanolamine molecule and the saccharinate anion, respectively, crystallizes in the triclinic space group P (1) over bar (No. 2) with a = 9.4651 (5), b = 10.4365 (5), c = 11.9314 (6) Angstrom, alpha = 84.402(1)degrees beta = 78.313(1)degrees, gamma = 75.307(1)degrees, Z = 2, V = 1115.11(10) Angstrom(3). The structure consists of isolated [Hg(ea)(2)(sac)(2)] units in which the Hg(II) ion is octahedrally coordinated by two nitrogen and two oxygen atoms of two neutral ea ligands, and two nitrogen atoms of two sac ligands. The ea acts as a bidentate N- and O-donor ligand and occupies the trans positions of the equatorial plane of the coordination octahedron forming a five-membered chelate ring, while sac behaves as a monodentate N-donor ligand occupying the axial positions. The average Hg-N-sac and Hg-N-ea bond distances are 2.739(3) and 2.114(7) Angstrom, respectively. The crystal exhibits extensive hydrogen bonds between the hydroxyl and amine hydrogen atoms of the ea ligands and the sulfonyl, carbonyl and amine groups of the sac ligands.