Hard coal deposits occur in Poland in three regions: the Upper Silesian Coal Basin (Gornoslaskie Zaglebie Weglowe - GZW), the Lublin Coal Basin (Lubelskie Zaglebie Weglowe - LZW) and the Lower Silesian Coal Basin (Dolnoslaskie Zaglebie Weglowe - DZW). At present coal mining operations are performed only in two of those regions: in GZW, which traditionally has always been the main source of Polish coal and where most of the mines are situated, and in LZW. The third region, DZW, has a historical significance only.
The surface area of the Upper Silesian Coal Basin (GZW) within Poland is estimated at about 5,800 km2. Mined deposits take up an area of about 1,100 km2 (i.e. about 19 % of the total area), reserve deposits that have been surveyed in detail occupy an area of 660 km2 (11 %), reserve deposits that have been pre-surveyed - 765 km2 (13 %), and exhausted and abandoned deposits - 635 km2 (11 %). About 27 % of the region are prospective deposits, where the resources were estimated to the depth of 1000 m. The remaining area comprises mainly regions with prognostic resources and overburden in excess of 1000 m and marginal parts of the basin without economic reserves of coal. At present about 78.5 % of coal balance deposits in Poland occur in GZW.
The Lublin Coal Basin (LZW), and in particular its extent, has been relatively poorly investigated. The area of 9,100 km2 is assumed to be a prospective area for coal deposits and with overburden thickness ranging from 360 m to over 1,000 m. The one deposit being exploited occupies an area of 57 km2, which constitutes 0.5 % of the total basin area. Deposits surveyed in detail take up an area of 340 km2, deposits where only preliminary surveys have been made occupy an area of 610 km2. In large part of the area the overburden is over 1000 m thick. Balance hard coal resources of LZW constitute about 21.5 % of total Polish balance resources.
Proven balance resources of hard coal, as estimated for 31.12.2003, amount to 43,122 million tons. Steam coal constitutes about 2/3 of the resources, the rest being coking coal. The resources of mined deposits make up about 37 % of balance resources and amount to 15,971 million tons. Commercial reserves of hard coal are estimated at 7,102 million tons, of which 75 % may be economically mineable.
 Balance resources - resources of deposit or its part which, taking into account natural conditions, can be considered for exploitation.