Considering the importance of recycling of agro-wastes, effects of soil application of several medicinal plant wastes in the tomato and cucumber cultivation were studied on the biological characteristics of the two major tomato and cucumber pests, tomato leaf miner, Tuta absoluta, and melon aphid, Aphis gossypii. In a preliminary experiment seven medicinal plant wastes including artichoke, rosemary, thyme, chamomile, nettle, fenugreek and caraway were used and wastes with a negative effect on plants growth were excluded from the study. In the next experiment, effects of three levels of wastes, 10, 20, 40 gr/500gr soil were investigated, including caraway, artichoke, chamomile and nettle wastes on tomato and tomato leaf miner and wastes of caraway, chamomile and nettle on cucumber and melon aphid. Results of assessed plant parameters showed a significant increase in plant height, leaf numbers, shoot dry weight and root dry weight of both of tomato and cucumber in all of tested waste treatments than that of control treatment and the highest increase was observed in plants treated by ¬40gr nettle/500gr soil. The highest amounts of nitrogen, potassium, phosphor and phenol were observed in plants treated by nettle (¬40gr/500gr soil) and chamomile (40gr/500gr soil). To determine the effect of medicinal plant wastes on the tomato leaf miner, two different trials, choice and no-choice tests, were used. In the choice test, the application of wastes reduced the percentage of infested leaves to the moth eggs and the mean number of eggs per leaf, and the lowest amount was observed in nettle (20 and 40 gr/500gr soil) and chamomile (40gr/500gr soil). In the no-choice experiment, the larval mortality of tomato leaf miner was increased up to 39.28% in nettle waste (40gr/500gr soil). In addition, the number of eggs laid per female was reduced 15% in moths reared on plants treated by nettle waste (40gr/500gr soil) copared to moths reared on the control plants. The effects of tested wastes on the melon aphid population on cucumber plants were studied in three experiments, antixenosis, antibiosis and tolerance tests. Results of the antixenosis test indicated that the numbers of aphids significantly reduced especially after 72 hours on plants treated by wastes than that of control plants. The nymphal development time and the number of nymphs per female were not affected by the waste application in the antibiosis test, but the total number of nymphs and adult longevity were significantly decreased in treatments compared to the control. Based on the results of tolerance experiment, cucumber plants treated by medicinal plant wastes were more tolerant to the aphid infestation than that of control plants and the lowest decrease in root and shoot dry weight and plant height were recorded in plants treated with nettle (40gr/500gr soil). According to the results it seems that application of accurate type and precise amount of medicinal plant wastes in tomato and cucumber growing media, by increasing the plant growth and reducing the herbivorous insect fitness, can affect the population of these two important pests. Key Words : Nettle, Antibiosis, Pod media, Greenhouse cultivation