Spraying of organophosphorus insecticides (OPI) using high volume technique may result in poisoning cases among farmers or inhabitants in the spraying zone. This study reported a case among farmers in Gaza Strip, Palestine and discussed the follow up treatments. Results showed sever fasciculation of tongue and all muscle, pinpoint pupils not reacting to light, losing consciousness and disoriented, irritability, followed by diarrhea, vomiting, and severe inhibition of acetyl choline esterase (ACHE). Irritability and low level of ACHE activity were the unique syndromes of this case. Management of the poisoning with Atropine injection was not successful treatment to cure the case. Treatment with Toxogonin as intravenous injection resulted in relieved the irritability of the poisoned case and cure the patient at the end point. During the six weeks of follow up period, the case was severely poisoned in the 1 st week, moderate poisoned in the 2 nd week and slightly poisoned at the 3 rd week. A medical decision to release the patient was made after ACHE activity level reached 4750 U/L, which very close to the normal range. The farmers left the hospital after three weeks of medical treatments and follow up. It is recommended to use Toxogonin in the management of poisoned cases with OPI immediately on arrival of cases with losing consciousness.