In this study, the k(0)-NAA standardization method was applied to determine manganese concentrations in commercial manganese ores that collected different mining sites in Turkey. The samples were grinded, sieved and filled into Teflon tubes with a thickness of 1mm and then irradiated in one irradiation cell of the 37GBq M-241-Be isotopic neutron source. The activities of the irradiated manganese-ore samples were produced via Mn-55(n,gamma) Mn-56 reaction and were measured by using a n-type coaxial HPGe detector with 78.5% relative efficiency. The peak area analysis of the 846.8 keV (98.85%) and 1810.7 keV (26.9%) gamma-ray lines of 56 Mn product radionuclide were performed. Experimental data of the Au-197(n,gamma) Au-198 standard monitor reaction, the neutron flux parameters in the irradiation cell and related nuclear data were used together to determine manganese concentrations in the samples. The manganese contents in five different mining sites were found to be 2.63 +/- 0.23(%) for MH (Malatya Hekimhan), 13.78 +/- 0.98(%) for EA (Elazig-Akboga), 21.53 +/- 1.52(%) for AK (Ankara Kalecik), 34.09 +/- 2.38(%) for AB (Adiyaman Besni), 41.36 +/- 2.89(%) for AG (Adiyaman Golbasi). The results indicated that k(0)-NAA method with use of an isotopic neutron source can be successfully applied to the analysis of manganese ores.