A patient is reported presenting a cerebellar disorder developing about 5 weeks 
after acute exposure to an organophosphate insecticide. Initially no major 
cholinergic features were observed. The ataxia of delayed onset was not 
accompanied by clinical or electrophysiological signs of polyneuropathy. The 
possible pathogenetic mechanisms are reviewed and discussed. This case 
illustrates the need to closely monitor all patients intoxicated with such 
chemicals for at least 5 weeks. One should not only keep in mind the well-known 
late-onset polyneuropathy, but also the less frequent delayed central nervous 
system effects, even in the milder cases where initial signs of acetylcholine 
excess are only minimally present or lacking.