Water availability is one of the most important factors which limits vegetable crops productivity, so it is necessary to change/modify irrigation practice that enable plants to adapt/overcome the limited water. Therefore, the main objective of the current investigation is to assess the effects of irrigation intervals and some anti-transpirants i.e., magnesium carbonate, kaolin, sorbitol and gelatin on sweet pepper performance during the seasons of 2021 and 2022. The experimental findings showed that all irrigation intervals and anti-transpirants significantly affected all studied parameters. Irrigation every 6 days gave the highest values of all parameters except for total chlorophylls, carotenoids, anti-oxidative enzymes activity which recorded the best values when plants irrigated every 14 days. Also, all studied parameters responded positively to all applied anti-transpirants, while leaf transpiration, weight loss, post-harvest decay percentage, respiration rate, and chilling injuries responded negatively. The maximum values of Malondialdehyde, 2,2-Diphenyl-1-picrylhydrazylradical scavenging activity, cell membrane stability, and number of fruits were obtained when plants irrigated every 6 days and sprayed with either kaolin or sorbitol. Additionally, either irrigation every 10 or 14 days and spraying with magnesium carbonate or kaolin increased fruits yield. Irrigation every 14 days and spraying with gelatin recorded the best values of total chlorophyll pigments, carotenoids, anti-oxidative enzymes activity, ascorbic acid, acidity, total soluble solids, calcium, and potassium contents in sweet pepper fruits. Conversely, the maximum values of leaf transpiration, respiration rate, and chilling injuries were recorded with all irrigation intervals in the absence of anti-transpirants.