The Thermoelectirc power plant Plomin (TPPP), Croatia is located in the middle of the eastern coast of Istrian peninsula (Northern Adriatic), and is considered to be the prime polluter of air in Istria. Between 1970 and 2000, mainly the coal from the local coal mine (Raša) was used. Coal contains between 10 and 14 wt. % of sulphur, and is considered as high organic sulphur coal. In the master thesis we established the level of soil contamination with sulphur in the vicinity of TPPP. 11 soil samples were taken and were analysed together with 3 samples of ash and 6 samples of high-S coal. Soil samples were taken at different distances from the power plant in the prevailing wind direction (SW), the control sample was also taken at a distance more than 10 km away. The coal samples were analysed for total S, ash samples for sulphate and soil samples for sulphate and the organic (humic and fulvic) sulphur. Sulphur concentration in bulk samples, as well as isotopic composition of sulphur was determined by EA-IRMS (IsoPrime 100 with PyroCube). The concentration of sulphur in samples taken in wind direction was more than 100-times higher (4 wt. %) than at the control side (0.04 wt. %) and decreased rapidly with distance from the TPPP. The speciation analysis showed that majority of S (>95 %) is present in organic form, mostly bound to humic acids. The δ34SVCDT values of bulk coal are between −5.0 to −10.0 ‰. In most soil samples, bulk δ34S were positive (+7,0 do +20 ‰). The values of sulphate in soil range between 1.0 and 5.5 ‰, while in organic S are between -3,5 in +6,0 ‰. That indicates that the atmospheric deposition of 34S-depleted fly ash and sulphate deriving from coal are the main S sources. Some part of sulphur in soil is marine origin too. The ratio C:N:S was calculated and it is 180:9:1. Enrichment factor and geoaccumulation index results indicate that the soil nearby TPPP are strongly contaminated with sulphur.