The complete molecule of the title compound, C30H20N2Se2, is generated by a crystallographic inversion centre at the mid-point of the Se - Se bond. The dihedral angle between the isoquinoline-1-selenol group and the phenyl ring is 14.92 (2)°. The herringbone-like packing of the structure is supported by inter-molecular π-π stacking inter-actions with a shortest perpendicular distance between isoquinoline groups of 3.514 Å; the slippage between these ring systems is 0.972 Å, and the distance between the centroids of the six-membered carbon rings is 3.645 (3) Å. © 2008.