Hereditary coproporphyria is a rarely diagnosed disease and is one of the acute porphyrias. The classic mental, neurological and abdominal symptoms are often observed, but there appear to be atypical clinical features and laboratory findings that may lead to underdiagnosis. In an oral stomatology practice, a group of patients having oral conditions with unknown pathophysiology and multiple systemic complaints were evaluated for porphyrin abnormalities. Blood enzymes, urine and stool porphyrin panels were usually run. A large number of the patients had the clinical symptomatology and porphyrin abnormalities classically found in hereditary coproporphyria.