The continuous searching for new compounds that more effective is very important in the pest control field. That is because of the resistance in many pests to several pesticides. In the search for new biologically active compounds, extensive research is based on the synthesis of heterocyclic molecules. In this work, three new cyanoacetamide derivatives were synthesized and confirmed by IR spectra, mass spectra and elemental analysis. These compounds were; (1): 2-cyano-N-(2-hydroxyphenyl) acetamide, (2): (E)-2-cyano-N-(2-hydroxyphenyl)-3-(methylthio)-3-(phenylamino) acrylamide and (3): 1-(2-hydroxyphenyl)-4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile. They were tested as active ingredients against the 3^rd instar larvae of cotton leafworm Spodoptera littoralis (Boisd) and the adult stage of cotton mealybug Phenacoccus solenopsis under laboratory conditions. Based on the mortality percentages and LC₅₀ values, all compounds had high toxicity against Phenacoccus solenopsis after 48 hours of treatment. While the second compound was more toxic against Spodoptera littoralis compared with other both compounds that had a very low toxicity.