A case of acute lead poisoning due to intravenous injection of lead acetate is reported. The patient developed clinical and biochemical symptoms characteristic for acute hepatic porphyrias. Elevated urinary 5-aminolaevulinic acid and low porphobilinogen correlated to a lead-induced inhibition of 5-aminolaevulinic acid dehydrase with diagnostically indicative reactivation rates by zinc and dithiothreitol. Urinary coproporphyrin excretion was also increased. Additional findings included anaemia and toxic hepatitis. Under the influence of elimination therapy with D-penicillamine pathologic parameters normalized. Except for transient neuralgic pains the patient did not experience any neurologic dysfunctions, thus contrasting the findings in chronic lead intoxication.