The objective of this study was to investigate differences between four strains of chickens on laying hen productivity and egg quality under acute heat stress (AHS). The study consisted of 44 hens from each of the Fayoumi (FY), Golden Sabahia (GS), White Leghorn (WL) and Lohman Brown (LB) strains that were 30 weeks old. They were allotted to two groups (a thermoneutral temperature regime (26.0 ± 1 ºC) and the AHS regime (35 ± 1 ºC) and 55 ± 5% relative humidity) for six hours. Egg number and feed intake were recorded. After imposition of the AHS, four hens per strain per treatment were randomly selected and slaughtered to calculate the relative mass of various organs and the number of follicles. Acute heat stress decreased feed intake of all strains significantly. There was a significant interaction between temperature treatment and strain on feed intake, egg weight, surface area of egg, yolk index, yolk weight, and albumen weight and on the relative weights of the various organs, except for the gizzard. Thus, the magnitude of the effects of AHS was strain dependent, with GS seemingly being less affected than the other strains.