This paper reports the results of statistical analysis of oil shale production and consumption for lots of oil shale delivered by the Company Eesti Polevkivi (1996-1998) and variability of low specific calorific value in 1998. Based on the analyses of quality characteristics, statistical analyses of samples, data from mining and power enterprises, and considering the degree of variability of oil shale quality characteristics in space and time, recommendations are made to improve sampling methods and measures for increased stability of oil shale quality for consumers.