The rodenticidal effect of crude argel (Gomphocarpus sinaicus Boiss) leaves was carried out on Norway rat under laboratory and field circumstances with zinc phosphide in Menofyia  Governorate. The laboratory results proved that non-choice also, free - choice feeding tests gave the same trend; a bait  1% either zinc phosphide and  argel ethanolic extract excepted 100% mortality for Norway rat as well as shorter time to death for zinc phosphide treatment. Argel ethanolic extract bait was more accepted than zinc phosphide with 57.1 and 34.5%, respectively. Also cleared that zinc phosphide more toxic than argel ethanolic leaves extract whereas the acute oral LD₅₀ values were 0.255 and 85.78mg/kg b.w respectively, for rattus norvegicus. Oral administration of sub-leathal dose (¼ LD₅₀) of each compound induced a noticeable disfunction in (AST), (ALT) enzymes and TP levels as they increased in plasma at 24 and 48 hours after treatment indicating a hepatic damage. Aprolongation of the prothrombin time (PT) had occurred following administration of Argel leaves ethanolic extract indicating disorders in blood coagulation mechanism but no effect on (PT) was observed with zinc phosphide treatment. Under the field conditions, zinc phosphide caused 70.6% population reduction, While Argel leaves ethanol extract reduced 68.0% of Norway rat, Rattus norvegicus population, while the water extract gave the lowest value (11.3%).