The biological effectiveness of some insect growth regulators (the anti-moulting agent (teflubenzuron) and the neem seed kernel ex­tract (azadlrachtin)) were evaluated against all stages of the tortoise beetle Cassida vitiate Vill. infesting sugar beet plants at Kati' El-Sheikh Governorate during two successive seasons (1999/2000 and 2000/ 2001). This evaluation was conducted in comparison with one of the rec­ommended organophosphorus insecticide namely, profenofos. The obtained results showed that, profenofos was the most ef­fective compound against C. vittata under field conditions, but was very harmful against its associated natural enemies. Teflubenzuron and azadi­rachtin exhibited sufficient effectiveness as biorational compounds in controlling C. vitiate and showed much lower toxicity against its asso­ciated predators. These biorational compounds could therefore be involved in inte­grated pest management program against this pest on sugar beet.