The largest application of pentachlorophenol is as a wood preservative, for which it has been discontinued in the European Union since 2009. However, pentachlorophenol has been widely used as a herbicide, germicide, fungicide, defoliant, wood preservative, algicide, and molluscicide. Because of this, it became ubiquitous and could be found in brick walls, adhesives, insulation, leather, paints, canvas, textiles (not intended for clothing), railway sleepers, wooden piles, fence posts and lumber/wood for construction, ropes, etc. Continued use in Asia to clean ponds against schistosomiasis vectors has been reported. Pentachlorophenol was detected in samples of pork, beef, chicken, eggs, and chicken coop material (concentrations 11 ± 2.8 μg/kg). It was found in about 20% of the solid food samples of 257 children in the USA. Concentrations of pentachlorophenol in red wine ranged from 12 to 123 ng/l and probably originate from oak barrels used for aging wine and other spirits. Pentachlorophenol causes non-Hodgkin’s lymphoma in humans. Its urinary metabolites are pentachlorophenol and nonspecific tetrachloro-p-hydroquinone (TCHQ).