Potential toxicity and biological effects of apricot seed extract were tested on the cotton leafworm, S.littoralis. Results indicated that the concentration 0.5% gave 6.67% mortality on larvae after 2 days of treatment and increased to 20% after 7 days. At 5% cone., mortalities were ranged from 53.34 to 71.11% in 2-7 days. Concerning pupation and adult emergence, 0.1% conc. gave 40 and 26.67%. respectively. The corresponding figures were 6.67 and 2.22%. respectively with 5% conc. The untreated larvae gave 96.67% pupation and 93.33% moth emergence.