The cotton aphid, Aphis gossypii Glover, and tomato leaf miner, Tuta absoluta Meyrick, are important pests of some field and greenhouse crops. Considering the resistance development in crop pests to pesticides and environmental and human health problems caused by agrochemicals, research on plant extracts and other natural plant products in insect control is increasing. The objective of this study was to evaluate the lethal, repellent and antifeedant effects of acetone, ethanolic, aqueous and hexane extracts of Zataria multiflora , Capsicum annum , Lawsonia inermis , Althaea officinalis , Cynara scolymus , Matricaria chamomilla , Cedrus deodara , root and leaf of Urtica dioica on A. gossypii and T. absoluta . The insecticidal activity of 36 plant extracts were preliminary screened against the second nymphal instar of A. gossypii at 3000 and 5000 ppm and second larval instar of T. absoluta at 2000 and 5000 ppm. For each pest seven plant extracts with the high lethal activity ( 40% against A. gossypii and 50% against T. absoluta ) at concentration of 5000 ppm were chosen for full dose bioassays. Three plant extracts with the LC 50 values of lower than 6000 ppm for A. gossypii and lower than 4000 ppm for T. absoluta were selected to evaluate their repellency effect on A. gossypii and antifeedant effect on T. absoluta. The highest insecticidal activity against the second nymphal instar of A. gossypii was found in acetone extract of C. annum (LC 50 = 4860.2 ppm), followed by acetone extract of Z. multiflora, ethanolic and aqueous extracts of L. inermis , aqueous extract of A. officinalis , hexane extracts of C. scolymus and Z. multiflora with the LC 50 values of 5668.5, 5983.7, 6038.2, 6063.2, 6128.1 and 6392.4 ppm, respectively. The repellency experiment was carried out on A. gossypii adults using three selected extracts at five concentrations. The results showed that acetone extracts of C. annum and Z. multiflora and ethanolic extract of L. inermis caused 67.5%, 57.5% and 40% repellency, at the highest tested concentration (6000 pmm), respectively. The highest insecticidal activity against the second larval instar of T. absoluta was obtained in acetone extract of Z. multiflora (LC 50 = 3436 ppm), followed by acetone and ethanolic extracts of C. annum , ethanolic extract of L. inermis , hexane extracts of Z. multiflora and A. officinalis and acetone extract of L. inermis with the LC 50 values of 3462, 3909, 4204.2, 371.5, 4448.4 and 4938.3 ppm, respectively. The antifeedant experiment was carried out on second larval instar of T. absoluta using three chosen extracts at five concentrations. The results showed that acetone extracts of C. annum and Z. multiflora and ethanolic extract of C. annum caused 67%, 59.6% and 49.7% antifeedant activity, at the highest tested concentration (5000 pmm), respectively. According to the finding of this study the tested plant extracts have potential in the management of these two pests, however, further investigations on the effects of the extracts and formulations is essential. Keywords: Plant extracts, Insecticidal effect, Repellency effect, Antifeedant effect, Cotton aphid, Tomato leaf miner