Intermediate syndrome (IMS) typically occurs at 24–96 hours following organophosphate (OP) poisoning, after an acute cholinergic crisis, but before OP-induced delayed polyneuropathy. It is characterized by proximal muscle weakness and respiratory insufficiency, which is a major contributing factor of OP-related morbidity and mortality. We report an atypical IMS case showing rapid-onset ascending paralysis and respiratory disturbance with an acute cholinergic crisis occurring 4–5 days after skin exposure to OP.