First examples of luminescent MnII thiocyanate complexes are presented. A series of such compounds has been synthesized via the reaction of Mn(NCS)2 with bis(phosphine oxides), Ph2P(O)–X–(O)PPh2, where X = CH2 (L1), CH2CH2 (L2), CH2CH2CH2 (L3), CH2C(=CH2)CH2 (L4), C(=CH2)C(=CH2) (L5) and C≡C (L6). The L1, L3 and L4 ligands, when reacted with Mn(NCS)2 on air (EtOH/acetone, r.t.), produce chelate complexes [MnII(O^O)2(NCS)2]. Under similar conditions, L5 gives ionic complex [MnII(L5)3][MnII(NCS)4], whereas L6 affords chain coordination polymer (CP) [MnII(L6)2(NCS)2]n. By contrast, ligand L2 results in formation of mixed-valent chain CP [MnIIMnIII(L2)3(NCS)5]n. Complex [Mn(L4)2(NCS)2] and CP [Mn(L6)2(NCS)2]n display unique dual luminescence, i.e. the intraligand fluorescence (blue band) and MnII-centered phosphorescence (red band), the ratio of which is largely modulated by excitation wavelength. Through this feature, the luminescence color of these complexes can be smoothly tuned from deep-blue to red. Complex [Mn(L5)3][Mn(NCS)4] shows MnII-based phosphorescence only.