In the mononuclear salen-type complex, [Er(NO(3))(3)(C(18)H(20)N(2)O(4))], the Er(III) ion is ten-coordinated in a distorted hexa-deca-hedral geometry by six O atoms of three nitrate anions and four O atoms of the salen-like ligand. Inter-molecular N-H?O hydrogen bonds occur. The crystal structure is stabilized by inter-molecular C-H?O hydrogen bonds.