The title compound, C18H24N2Se3, consists of discrete molecules; owing to the presence of strong intramolecular N...Se interactions [N...Se = 2.671 (4) and 2.873 (4) A], the chalcogen Se atoms of the angular Se3 chain exhibit different coordination geometries, i.e. the terminal Se atoms are tricoordinated and exhibit a T-shaped environment of the CNSe2 core [N...Se-Se = 173.73 (9) and 172.29 (9) degrees], while the central Se atom is dicoordinated to the other two Se atoms, with an Se-Se-Se angle of 108.32 (2) degrees.