There is inadequate morphological nomenclature and definition of organ pathology when using wild fish in biomonitoring of environmental pollution. The aim of this investigation was to provide a guide that assesses histology of Shorthorn (Myoxocephalus scorpius) and Fourhorn (Myoxocephalus quadricornis) sculpins obtained from a study using these two fish species as bioindicator organisms to evaluate environmental impact attributed to a dumpsite located in East Greenland. Specific histopathological lesions were quantified on the basis of Bernet et al. and all lesions were photomicrographed, evaluated, and placed into specific categories of five reaction patterns. These were circulatory disturbances, regressive changes, progressive alterations, inflammation, and tumors based on anatomical location, type, and severity. This method is postulated to enable an objective assessment of the histological integrity of fish gills and liver; thus, making it possible to compare sculpin pathology and reaction patterns at different locations. Data suggest that this updated histological guide might be used for identification and quantification of histological lesions when applying sculpins in biomonitoring programs in Greenland and other Arctic regions.