Méthamidophos is an organophosphorus insecticide which delayed neurotoxicity is more frequent than with other organophosphates. Authors present a case report concerning a collective poisoning after cutaneous contact: two farm labourers presented moderate cholinergic signs quickly followed by proximal neurological signs (retrobulbar ocular neuritis for one patient, thight paresthesias for the second one). These signs decreased meanwhile new neurological symptoms appeared: sensory and motor peripheral neuropathy in both patients, with a clinical aspect of OrganoPhosphorus Induced Delayed Neuropathy (OPIDN). This unusual chronology and the disappearence of all signs at the 18th month, lead the authors to diagnose a collective methamidophos poisoning in three phases: first, anticholinesterasic acute syndrome; second, an intermediate syndrome and third an OPIDN.