A polymeric manganese(II) complex, [MnL2Cl2]n (L = 2-amino-4-methylpyrimidine) has been synthesized by the reaction between MnCl2·4H2O and L in the 1:1 and 1:2 metal-to-ligand molar ratios. The Mn2+ ions adopt distorted octahedral environment formed by four Cl− ligands and two N1 atoms of the pyrimidine rings of two L molecules. The chlorido-ligands adopt a μ2-bridging coordination mode linking manganese atoms into the polymeric chain. The free ligand L shows excitation-wavelength-dependent emission originating from the π-π* and n-π* excited states with nanosecond lifetimes in the blue region of the spectrum. The complex [MnL2Cl2]n demonstrates photoluminescence with the maximum in the near-infrared region (λmax = 740 nm, φ = 1.7%) with microsecond lifetimes (τ = 124 μs).