Heather Hills Elementary School in Prince George’s County, which was designated a National Blue Ribbon School in 1990 and a Maryland Blue Ribbon School in 2007, has a clear history of student achievement.

Last year, the school scored the highest scores on state reading and math assessments in the county, making it one of the top elementary schools in the state.

So why have a group of parents who have children at the school complained for weeks about what they describe as an overbearing environment? A school where students are berated for not having a pencil or for asking to go to the bathroom?

One parent used the word “toxic” to describe the culture.

“The lack of respect for students, parents and the volunteers is what makes it toxic,” said Alexandra Calloway, a parent.

A parent complained that her child’s study guide was the same as a test. Her child’s grades have dropped from A’s to as low as a C.

They demanded a change in leadership.

Principal Patsy Hosch, contacted Tuesday via e-mail for a response, did not reply.

Meanwhile, another group of parents and teachers recently told the school board and administration that the level of achievement at Heather Hills was a “shining example” of the type of success that could be obtained in the county schools.

“We can no longer sit back and let a few disgruntled parents stand before you and twist the truth,” said Denise Hazard, a teacher, during a recent board meeting.

Hazard said the school, which offers gifted and talented programming, provides a rigorous curriculum. It also has a weekly enrichment program that includes chorus, photography, sign language, robotics and poetry.

“Don’t let a few people ruin our reputation,” she said.

Michael Sullivan, a parent, thanked the school system leaders for the “rigid” and “stressful” curriculum. He said his son, who had to adjust to taking tests and doing homework after attending a Montessori school, has excelled at Heather Hills.

“I feel blessed and my family is blessed,” he said.