Nowadays, the growing interest in the photochemistry of d10 metals coordination compounds in the forms of discrete and polymeric species resulted in electroluminescent materials used in OLEDs [1]. In continuation of our recent study [2], we prepared two Cd(II) polymorphic complexes based on the photophysically intriguing triimidazole (triimidazo[1,2-a:1',2'-c:1'',2''-e][1,3,5]triazine) ligand (L) [3]. Mononuclear complexes of formula [Cd(H2O)2(NO3)2(L)2] were obtained by one-pot reaction of Cd(II) nitrate hydrate with L. The prismatic crystals 1 are monoclinic, sp. gr. C2/c, a=25.8206(13), b=6.9849(5), c=13.5066(6) Å, β=101.938(5)°, V=2383.3(2) Å3; Dcalc=1.864 g/cm3. The plate crystals 2 are monoclinic, sp. gr. P21/n, a=7.2334(2), b=14.0028(4), c=22.4443(6) Å, β=91.314(3)°, V=2272.7(1) Å3; Dcalc=1.955 g/cm3. The Cd(II) atom in both forms coordinates in trans-positions two L ligands, two NO3-anions, and two water molecules. Complex 1 resides on an inversion center providing an arrangement of L ligands in parallel planes, while 2 lies in a general position with the two L ligands twisted by 52.54^O (Fig., a). The Cd-N distances are equal to 2.347(2) Å in 1, and 2.356(3) and 2.360(3) Å in 2. Layers of O-H…O bonded complexes parallel to ab plane and interconnected by stacking interactions are present in both polymorphs. Parallel infinite pillars of uniformly stacked centro-symmetry related L with interplanar separations 3.378/3.432 Å are observed in 1. In 2 the triimidazole ligands are united in centrosymmetric dimer with interplanar separation of 3.220 Å and greater overlapping with respect to 1 (Fig., b). Preliminary photophysical characterization revealed a rather weak emission for 1 and a stronger one for the denser polymorph 2 in agreement with L greater stacking interaction [3].