Regional high school principal Stephen Nixon has resigned his post, Vineyard schools superintendent Dr. James H. Weiss confirmed on Monday afternoon.

Mr. Weiss notified school parents and teachers of the decision Monday in a notice that went out on the school ed line.

“I am writing to inform you that late last week I granted Dr. Stephen Nixon a leave of absence from his position as principal of the Martha’s Vineyard Regional High School. Today, Steve submitted a letter of resignation effective at the end of the current school year. I know I speak for everyone when I wish Steve the best.”

Reached by telephone Monday afternoon, Mr. Weiss said Mr. Nixon was out on medical leave for a condition that the superintendent said was not life threatening. “It came suddenly today,” he said, speaking of the resignation. “I knew he had been dealing with some health issues but I would say I was surprised to get that today.”

Mr. Weiss has appointed assistant superintendent Matthew D’Andrea as acting principal, effective Tuesday. “He will work hard with staff to create a smooth transition,” he said.

In an email to the Gazette later in the afternoon, Mr. Nixon said he had been having health issues for much of the school year and that he had sought a medical leave based on the advice of his doctor. He provided a copy of his letter of resignation, where he praised the school, staff and students and said his family was exploring a move off the Island.

Mr. Nixon, 57, was hired in 2008 to succeed Margaret (Peg) Regan who stepped down from her post that year.

He was assistant principal at the time and was chosen over more than a dozen off-Island candidates who had applied for the position.

“I went for the inside man,” Mr. Weiss told the Gazette at the time, citing Mr. Nixon’s direct experience in the running of the high school and his working knowledge of the Massachusetts school system as factors.

“He’ll hit the ground running at a critical time for the school,” Mr. Weiss said. It was a time of tight budgets and declining enrollment, and Mr. Weiss cited Mr. Nixon’s skills in the political end of the principal’s position, which involves dealing with leaders from the six towns and negotiating budgets.

Mr. Nixon moved to the Island from New Jersey in 1998 and began teaching history at the high school.

He took his first administrative position as temporary dean of students in 2002 and was named assistant principal in 2004.

As principal, Mr. Nixon has been responsible for managing curriculum, a 700-plus student body and a multi-million dollar annual operation funded by Island towns through their budgets. He is an amateur musician and known for playing the guitar at graduation every year.

But his five-year tenure has been marked by some bumpy moments with school culture, including a controversy in June 2010 when 10 graduating seniors who were Brazilian wanted to wear scarves in their native country’s colors over their graduation gowns. Mr. Nixon denied the request citing school policy, but was later overruled by the school committee.

Early this year there was tension between Mr. Nixon and upper classmen over his handling of an incident when brownies laced with marijuana had been brought into the school.

Mr. Weiss praised Mr. Nixon’s work in establishing an alternative education program, a therapeutic support program for special education students and a vocational program in health assisting.

“I think if you look at the test scores in the past few years we have had some of the highest test scores in the school’s history,” he said.

Mr. Weiss said a search for a new principal would begin as soon as possible.

The complete text of Mr. Nixon’s resignation letter follows:

“After spending 16 wonderful years at Martha’s Vineyard Regional High School I realize that I have accomplished many of the goals I set out to tackle when I moved into administration. We have an in-house alternative program, a therapeutic support program, some of the highest test scores in school history, a freshman year that totally changes our perspective on the transition year, and the introduction of a new nursing program to name a few.

“Recently our family has looked at a lot of opportunities that have presented themselves to us, most being off-Island, and we feel the time is right for us to take advantage of these, as we look to the final years of our professional careers. So, it is with great sadness, and yet a feeling of excitement, that I would like to announce my resignation as principal of Martha’s Vineyard Regional High School effective June 30, 2014.

“It has been an honor to work with some of the greatest teachers and administrators in education. It has been a privilege to work with so many dedicated, parents, community members, and town governments. Most of all it has been life changing working with the greatest students anywhere.

“I wish you all well and our family will always have fond memories of you and you will be greatly missed.”