When you are looking for a quality Montessori school it is important to keep in mind that the name “Montessori” is not copyrighted or trademarked in any way. So anyone can open a school and call it Montessori and any school can claim that it is offering an authentic Montessori program. Schools are operated independently and are either privately owned or run by a non-profit association. The vast majority of schools calling themselves "Montessori" do offer a high quality and authentic Montessori program but a little research on your part can ensure you are making an informed choice for you and your child.
It is usually the case that a Montessori school administrator will encourage parents to observe at the school before enrolling their child. This is an excellent way to assess if the school will be an environment that will suit the developmental needs of your child. You will be invited to observe in a classroom setting while the children are in attendance. Typically you will be offered a brief history of the school, program offerings and school policies. It is important to enquire about the training and experience level of the teachers and whether parent education evenings are offered. You might also consider asking if the school has an affiliation with a recognized Montessori organization.