The aim of the present study is to investigate the effect of classroom interior design with or without students’ participation on their shyness and educational performance. 60 ninth-grade students of Shiraz City in 2015¬-2016 who were selected by means of random cluster sampling answered the questionnaires of Cheek and Buss in three groups during three stages of pre-test, post-test, and follow-up. Their educational performance during these three stages was calculated on the mean of mathematics, experimental sciences, and literature. The results of repeated measures analysis of variance (ANOVA) indicated that there is a significant relationship between classroom interior design and variables. The results also indicated that there is a significant relationship between students’ participation and non-participation in classroom interior design and variables. Furthermore, participation and non-participation in classroom design had an effect on students’ educational performance. Due to the effect of environment interior design on people inside it, environments that have the best effect on students can be created in order to nurture their talents.
