A Catholic school in Hamilton is taking a pass on Halloween this year, asking parents and students to leave the costumes at home.

The St. Therese of Lisieux Catholic elementary school said students should not dress in costumes on Monday because it distracts from the school's focus on education.

In a "gentle reminder" sent to parents, school administrators said Halloween costumes were not welcome because they cut into instructional time and also raised safety and privacy questions for students.

The letter noted that in the past adults were on site helping students change into costumes and taking photographs without permission.

Students and staff were free to wear black and orange clothes rather than a costume, the letter read.

If the child did not wear black and orange, they were expected to wear the school uniform.

In an email sent to CTV News, parent Lynda Fraser said the school's decision to "cancel" Halloween was doing a disservice to the students.

"Halloween is an event all children look forward to every year. While they can still have their fun and celebration at home and in the evening, many children look forward to the school day celebration where they get to wear their costumes for their friends and have a class party," Fraser wrote.

She added that students tend to lose focus and get worse grades when they don't enjoy school.

The Catholic school said it would emphasize the Christian origin of Halloween by beginning the day with a Liturgy of the Word.

Halloween treats were also discouraged from the school events, with staff asking that parents encourage healthy snacks and sharing non-edible treats such as stickers and erasers.