Ill Estonia there is the largest industrially-used oil-shale basin ill the world. This review addresses the environmental hazard of the waste streams of oil-shale industry via solid waste- and water-path, mainly focusing oil ecotoxicological risk due to open semicoke deposition inducing hazard to surrounding soils and groundwater. This is the first comprehensive ecotoxicological review of available data on oil shale industry pollution ill Estonia as well as world-wide.