Bread wheat is the widely growing cereal crops in Trakia region and various environment conditions reducing grain yield. The aim of this research was to determine the effects of canopy temperature at different growth stages in bread wheat genotypes on yield and yield component under rainfed conditions. Research was carried out at Trakya Region, Turkey, in 2017-2018 growing years at 4 locations with 25 genotypes in randomized completely blocks design with 4 replications. Canopy temperature, chlorophyll content, days of heading, grain yield, plant height, peduncle length, spike length, number of spike per square meter, number of spike per spike, number of kernel per spike, and spike weight and also, relationship among these characters were investigated. For determining canopy temperature of the genotypes data was taken at four different plant growth stages (Z41, Z55, Z60 and Z70). The analysis of variance revealed highly significant differences among the genotypes for grain yield, plant height, days of heading, chlorophyll content, number of spike per square meter, peduncle length, spike length, number of spike per spike, number of kernel per spike and spike weight. Mean grain yield of the genotypes was 616.1 kg da-1, and the highest yields were obtained in G21 line with 680.7 kg da-1 and followed by cultivar Köprü (677.6 kg da-1). Correlation coefficients based on the investigated parameters were determined by Pearson’s correlation analysis. Grain yield was negatively slightly correlated with canopy temperature at booting stage (Z41) and negatively significantly correlated at Z51 growth stage (r=-0.534**). A significant positive correlation was determined between grain yield and chlorophyll content at Z55 growth stage (r=0.600**). It was found significant positive correlation between grain yield and number of spike per square meter (r=0.416*) and, peduncle length (r=0.469*). A negative correlation was observed between chlorophyll content with canopy temperature at Z41 (r=0.595**), and Z55 (r=0.586**) growth stages. A moderate negative correlation was found between spikelet number per spike with canopy temperature at Z61, and at Z70. The correlations among physiological parameters revealed that canopy temperature and chlorophyll content were positively associated with grain yield; hence these components can be used as reliable selection criteria to improve grain yield in wheat. Thus estimation of correlation analysis among yield and yield components and, physiological parameters may provide effective selection criteria to improve bread wheat grain yield.