The present study was conducted at the Experimental Farm, Fac., Environ. Agric., Sci., Arish Univ., during successive summer seasons of 2018 and 2019, to screening twenty one genotypes of tomato as well as Galaxy 040 F1 as check to high temperature under North Sinai conditions. The analyses of variance for all studied traits revealed that mean squared of genotypes were highly significant under high average day/night-time temperature (34.6 oC and 23.9 oC, respectively) of two seasons. The studied lines CLN 1621F, Rio Grande and CLN2514A were the best for floral traits. However, the superior genotypes for fruit set percentage were CLN2026D and Rio Grande. Results of screening revealed that CLN2514A was the best for no. fruits/plant, CLN2413D and CLN1466EA for average fruit weight and CLN1621F for fruit yield /plant (2.84 kg). The highest content of proline recorded by CLN1621F and CLN3125L. Tomato genotypes ranked based on cumulative score to tolerant, moderately tolerant, moderately sensitive and sensitive groups. The clustering pattern of tomato entries grouped into five clusters. The clusters 1, 3 and 4 consisted of three genotypes, whereas the clusters 2 and 5 involved nine and four ones, respectively. Principal component analysis revealed that first two components participating 81.3% of total variability. The highest contribution towards total variability in PC1 and PC2 reflected by no. pollen grains/anther, pollen viability%, branches/plant, fruit set%, fruit yield/plant, average fruit weight, no. seeds/fruit and proline content traits, suggesting that these traits might be taken in concern for successful selection of tomato genotypes under high temperature.