School generally commences on or before August 13th of each year. New student/parent orientation for MS and HS are scheduled the day before school opens. School usually ends after the first week in June of each year. You will find that the ISB calendar consists of the same number of instructional days as US schools. Please check the calendar in the Admissions section of our website for the most up-to-date information

Classes at ISB begin early and end early in order to beat the Bangkok traffic. Classes in the ES begin at 7:35 AM and end at 2:20 PM. Classes in MS and HS begin at 7:20 AM and end at 2:25 PM. After school activities in ES and MS generally run from 2:35 – 3:35.

Montri Transportation Company has been providing transportation services to ISB since 1976. Montri will provide transportation services for students up to 50 kilometers away. Each bus is air-conditioned and has retractable seat belts and a bus supervisor. Service is door-to-door for all students before school and immediately after school at 2:20 PM. There is an Elementary after-school activity bus at 3:30 PM which also offers door-to-door service for students in grades Kg – 5. Middle School and High School students also have 3:30 bus service that travels on the main routes. Students will be dropped off on a main route at a point closest to their home. For many students, this means a short walk into a Soi (lane). High School has an additional 5:00 bus with the same arrangements.

For ES the maximum class sizes are as follows:

  • KG 17 students; 1- 2, 20 students; Grade 3, 21 students; Grades 4-5, 22 students
  • The average Middle School class size is 17 students.
  • The average High School class size is 15 students.


ISB has uniforms for sale at the ISB bookstore on our campus. The uniform consists of a polo shirt with the school emblem with either khaki or black shorts, pants, or skirt. Physical Education (PE) uniforms are required at all levels. This is a unisex uniform that consists of black knit shorts and a gray ISB T-shirt. Elementary students wear the PE uniforms to school on the day they have PE classes. MS and HS students change into their PE uniforms before PE class in the locker rooms provided.

Our Middle School/High School (Main) cafeteria is open from 7 AM – 5 PM. This cafeteria sells breakfast, snacks, and hot lunches. The main cafeteria also has a cold kitchen that offers salads, sandwiches, and fresh fruit. Meals in the Main cafeteria are ala Carte and can be purchased with cash or ISB ID cards can be used as Smartcards to make cafeteria purchases. The Elementary School has their own cafeteria for grade Kg – 5. Lunch and snacks in the Elementary cafeteria are included in tuition. The Elementary cafeteria offers a choice of an Asian entrées, Western entrées, Chinese noodle soup, or sandwiches each day. There is also a fresh fruit and salad bar.

Once their children have been admitted to ISB, parents will be issued and ISB ID. This ID will allow parents to use the libraries and sports facilities, such as the tennis courts, weight room, and track, at ISB.

A great deal of effort is invested in creating balanced classrooms in order to provide for the most effective instruction. We try to balance each ES and MS classroom in terms of gender, nationality, language proficiency, academic ability, and maturity level. Parents may complete a class placement form, available in the ES counseling center, if they wish to have a voice in the class placement process.

If you would like to be put in touch with a parent at our school via e-mail, please send an e-mail to the ISB Admissions Office at and they will forward your mail to an ISB parent. Please include your home country, the age of your child(ren), and any other relevant information about you and your family in the email so that an appropriate match can be found.