This article investigates the natural radioactivity of 26 ash samples, laboratory produced from lignite samples collected in the West Macedonia Lignite Center in Northern Greece. The activity concentrations of 40K, 235U, 238U, 226Ra, 228Ra, and 232Th were measured by spectroscopy and found four to five times higher than those in the original lignite samples. The radionuclides transfer factors depend on the characteristics of the combustion process and were found higher for 232Th, 228Ra, and 40K, because of their closer affinity with the inorganic fraction of the lignite. Compared with other results found in the published literature, the studied ash has relatively high content in radioactivity, but the resulting radiation dose from the radionuclide emissions in the West Macedonia Lignite Center do not contribute significantly to the total effective dose.