Impact of planting dates in different agro-ecosystems on pest-predator interactions in untreated cotton fields at three plant growth stages; Plant Establishment (PE), Fruit Formation (FF) and Fruit Matura­tion (FM) was studied in Egypt at Mallawi and Sakha Research stations in the two successive cotton seasons 1992 and 1993. Direct counts of pests and predators were taken weekly from the two planting dates/ location/season. Population of cotton pests and their associated preda­tors was substantially different in the two areas and in the two planting dates; Early (E) and Late (L). Highest infestation rates by secondary pests were recorded in E and L plantings at Mallawi and Sakha, respec­tively in the two seasons. L plantings received higher populations of the key pests; CLW, SBW and PBW than the E plantings in the two locations and seasons except at Mallawi, 92 in case of the CLW. Generally, preda­tors population was almost higher at sakha than at Mallawi as well as in the E plantings than the L ones in the two seasons. Highest population of predators was recorded during FF stage (by mid-season). Statistical analyses showed different significant interactions between most of pre­dators and both secondary and primary insect pests of cotton during various plant growth stages. The interactions were obviously more sig­nificant at Sakha.