It was investigated in a small-scale study using a climate-controlled room at IAPGR, Roslin, that the effects of feeding a high level of supplemental vitamin E (500 mg/kg) on egg production and plasma concentrations of egg-associated metabolites in laying hens subjected to a short exposure (7 days) to a moderate heat stress (temperature of 32°C). The study showed, on small group sizes (12 birds / group), that in control birds (fed 30 mg supplemental vitamin E/kg), this degree of heat stress depressed egg production by about 30%. In the birds receiving the high level of vitamin E, egg production was maintained at levels very close to those prior to the heat stress. The objective of this experiment was to confirm in a larger scale the effects of high levels of dietary vitamin E on egg production of hens exposed to a chronic heat stress and during a period of recovery at thermoneutral temperatures.