This study was conducted at the Experimental Area of Cukurova University in 2015 and 2016 as a double crop growing season. The objective of this study was to determine the effect of high temperature on seed yield and some yield component of soybean [Glycine max (L.) Merr] varieties in double crop growing season in Mediterranean region in Turkey. The experimental design was a Randomized Complete Block with three replications. The Arisoy, Atakisi, Ataem-7, Umut-2002, Turksoy, Adasoy, Cinsoy, Ilksoy, Bravo, Sa-88, S.4240, Blaze, Nova, May-5312, Cetinbey, May-5414 and 34A7 varieties (belonging to maturity groups II, III, IV and V) were used as a plant material in this research. The maximum air temperature data was recorded day by day during the growing period in both years and daily maximum air temperatures were higher in 2016 than in 2015. When the seed yield compared in 2015 and 2016, it is found that the seed yield was lower (29.5%) in 2016 than in 2015. The high temperature was negatively affected the seed yield of soybean varieties. It was found that the soybean varieties differ in their sensitivity to high temperatures.