The purpose of this study was to investigate if there was a significant difference in attitudes towards school, academic self-efficacy, and perceived social adjustment of Year 7, Year 8, and Year 9 students at an International School in Bangkok, Thailand. This research was a quantitative comparative design utilizing three questionnaires: the School Attitude Questionnaire by Seker (2011), the Academic Self -Efficacy subscale from the Self-Efficacy Questionnaire for Children by Muris (2001), and the Student Adjustment to College Questionnaire by Baker and Siryk (1984) to collect data in this study. The three questionnaires were combined for the current study into the Student Overall Adaptability to School Questionnaire. The researcher collected data from 222 students from Year 7 (71 students), Year 8 (78 students), and Year 9 (73 students). The data were analyzed using descriptive statistics and a One-Way Analysis of variance for statistical hypothesis testing. The study indicated that the students had positive attitudes toward school. The academic self-efficacy towards school was moderate, followed by students' perceived social adjustment, which was slightly acceptable. There was a significant difference between the perceived social adjustment of Year 7, Year 8, and Year 9 students. Still, there was no significant difference between students' attitudes towards school and academic self-efficacy of the Year 7, Year 8, and Year 9 students. Recommendations are provided for teachers, parents, school administrators, school counselors, and future researchers.  
