Summary This paper describes a case of organic mercury poisoning in a child from a mercury‐intoxicated family. The condition has not hitherto been reported among children. The child was poisoned after eating porridge prepared from flour which had been treated with an dkyl mercury compound, panogen, which is used by farmers in seed dressing. The main clinical signs and symptoms are due to severe damage to brain tissue, and thus differ from the parenchymatous lesions resulting from inorganic mercury poisoning. Treatment with BAL was of doubtful value.