The diagnostic value of parakeratosis is reviewed, with special emphasis on associated inflammatory tissue reaction patterns and the geometric pattern of the scale. Parakeratosis may also occur in disorders not primarily inflammatory in nature and those associations are addressed. Topics are divided into 6 categories: parakeratosis in the settings of spongiotic and interface dermatitis, disorders in which neutrophils are a prominent feature, "patterned" parakeratosis, parapsoriasis, and disorders of keratinization. The entities considered are diverse and major diagnostic features of each are reviewed.