Keratocysts of the solitary type were histologically and histometrically compared with those associated with the nevoid basal cell carcinoma syndrome (NBS). It was observed that parakeratinization, intramural epithelial remnants and satellite cysts were a more frequent finding among NBS keratocysts than among solitary keratocysts. Conversely, it was also found that the total nuclear density was greater in non-associated cysts and that the total number of nuclei, the number of basal nuclei and the epithelial height values were also higher in solitary keratocysts. NBS-keratocysts and solitary keratocysts are considered to be two morphologically distinct populations of the same entity.