Dichlorotris-(2-methylimidazole)manganese(II), MnCl2(2-meim)a, is monoclinic with a= 8.189 (1), b= 14.763 (1), c= 14"419 A, fl= 108.69 (1) °, space group P21/c and Z=4. The structure has been determined from diffractometer data, and least-squares refinement with 2397 independent reflexions has reached R = 0.046. A monomeric pentacoordinate structure is found, in which the coordination, though severely distorted towards square pyramidal, is essentially trigonal bipyramidal. A C1 atom and a 2-meim ligand occupy the axial positions with Mn-C1 and Mn-N distances of 2-525 and 2"249 A respectively. For the equatorial groups the respective bonds are somewhat shorter -a C1 at 2.392 A and two 2-meim ligands with a mean Mn-N of 2.195 /~. The molecule has approximate m (C~) symmetry.