Field experiments were carried out in order to test the effect of phytoremediation and bioaugmentation for remediation of semi-coke. Four pilot test plots (each 50 m(2)) were established at semi-coke depository in July 2001. The growth rate of plants was approximately twice higher in the case of soil amendment. The phytoremediation increased the number of bacteria and diversity of microbial community in semi-coke. Within one and a half year period starting from establishment of test plots, the concentration of phenolic compounds decreased up to 35% and that of oil products up to three times compared to control. In bioaugmentation experiments the biomass of bacteria consisting of three strains isolated from nearby area was supplied in order to study the stability of microbial populations around root area favoring the biodegradation efficiency of phenolic and oil pollutants.