ABSTRACT The objective of this study was conducted to evaluate the effect of four botanical extract oils (clove oil, mint oil, garlic oil and Neemazal- T/S formulation [1% Azadirachtin]) on the biological aspects of the 4th instar larvae of Egyptian cotton leafworm, Spodoptera littoralis. The results cleared that the larval duration were 9.37, 9.17, 8.78, 8.89 and 10.00 days for clove oil, mint oil, garlic oil, Neemazal- T/S formulation and control, respectively. Clove oil caused the highest percent of larval mortality (92.67%), while the least one (59.55%) was recorded in case of mint oil. The pupation and emergence percentages were (7.33, 40.45, 32.44, 17.33 and 88.00 %) and (85.93, 82.67, 82.80, 75.53 and 97.00 %) for the abovementioned oils, successively. Neemazal -T/S formulation caused the highest significant reduction in fecundity percentage recording 224.44 eggs/ female, regardless of the concentration, while control female laid an average of 1703.33 eggs / female. All tested botanical extract oils caused positive effect on investigated biological aspects, especially both of clove oil or Neemazal- T/S formulation. Key words: Spodoptera littoralis, larvae, botanical extract oils, biological aspects.