By Eirin Combs, news correspondent

Walking down Massachusetts Avenue during the week leading up to Halloween, it is hard to miss the line of costume-seekers wrapping around the block. People from all over Boston come to Dorothy’s Boutique to find their perfect costume.

“One thousand people on the busy days, 500 on the not-so-busy days,” Dorothy’s Boutique store manager Jon Diamond said of the crowds they see right before the holiday.

Opened in 1947, Dorothy’s Boutique has been the year-round, one-stop shop for Bostonians to get any costume imaginable for decades. Located in the heart of Back Bay, Dorothy’s is a very accessible location to students from Northeastern University, Boston University and Berklee College, which makes it all the more popular. The boutique is packed with an extensive collection of costumes, vibrant wigs, fake facial hair, party supplies, theatrical makeup and accessories for any occasion.

However, Dorothy’s hasn’t always been a costume shop. Diamond has been running the store for 35 years after taking it over from his parents, who started the business selling regular clothing.

“Initially, it wasn’t a costume shop, it was more of a ladies’ boutique,” Diamond said as he shifted the sailors hat on his head. “When students came into this area, we thought it would be natural to convert the store and see what Halloween would do for us. It turned out to be a home run.”

An emphasis on Halloween costumes drew many people to the boutique in recent weeks, as it does every year. Many of these shoppers were college students from the surrounding area.

Casey Benzi, a second-year Boston University student, stood in line with a group of friends at Dorothy’s on Saturday. They all had different goals: Benzi was there in hopes of finding a toy chihuahua for her Paris Hilton costume.

“I love it,” Benzi said, nodding enthusiastically. “They have everything, and all year round for different themed parties.”

Myia Thornton, who studies music production and engineering at Berklee College of Music, was waiting in the long line to find a costume for a party that evening.

“I just wanted to go all out this year, because I usually don’t dress up,” Thorton said. “I just want to be something I’m not.”

Another student from Berklee College of Music, Peyton Huliganga, had been to Dorothy’s before but said she was surprised by the crowd that had formed.

“I’ve never seen it like this before,” Huliganga said as she glanced at the line of people in front of her.

While the weeks preceding Halloween are when the store sees most of its activity, it remains busy year-round.  On a normal day in January, the boutique has an average of 50 customers searching for costumes — 10 percent or less of the customer population the store sees during the costume-centric holiday. Dorothy’s moderate success in all seasons, however, is primarily because of its ability to promote all holidays and encourage various opportunities to dress up, Diamond said.

“As a costume shop we try to promote every holiday,” Diamond said. “We try to look for quality and we try to look for variety.”

Diamond said he did not expect to take after his parents and continue the family business. Even so, he is grateful to be able to continue the family legacy and enjoys the excitement the store brings.

“I got out of college and I took some time off,” he said. “I thought I’d never take over the store. It’s been an exciting 30-something years and I like continuing their legacy.”

Diamond said the store is so popular because of the extensive and eclectic inventory they offer, along with the friendly customer service and the affordable prices.

“Between the wide selection and our decent prices and good service, and the fact that we have everything and we’re one-stop-shopping, it’s kind of the recipe for success,” Diamond said with a smile.