Keith Hufnagel, a professional skateboarder who grew a San Francisco streetwear store, Huf, into a global apparel company by the same name, died on Thursday at his home in Los Angeles. He was 46.

A statement from the company said the cause was brain cancer, which Mr. Hufnagel had for two and a half years.

Mr. Hufnagel came of age as a skateboarder during the 1980s in New York City, where skateboarders formed a gritty subculture that used the urban environment as a playground. In 1992 he moved to California and became a professional, riding for companies like Real Skateboards, Thunder Trucks and Spitfire Wheels.

He was notable for his “pop,” the seemingly effortless way he leapt onto and over tall obstacles, and for his fluid lines through intimidating terrain, even while dodging traffic or speeding down a steep hill. He toured the world as a professional, and he appeared in indelible skateboarding videos in the middle to late 1990s and the early 2000s.

But around 2001, he said in a recent interview with the rare-sneaker sale site Goat, he began to wonder about his future after skateboarding.

“I’d been traveling for over a decade, seeing what was happening in Tokyo, New York, L.A., London,” Mr. Hufnagel said. “I was hitting all these major cities and seeing this streetwear and sneaker culture happening.”

So Mr. Hufnagel and his wife at the time, Anne Freeman, decided to open a boutique in San Francisco. Ms. Freeman wanted to focus on women’s apparel, but they found that the market was oversaturated.

“So I was like, ‘Well, I’d like to do a streetwear concept store of what I see around the world,” Mr. Hufnagel said. “We didn’t have a business plan or anything. We just made it happen.”

In 2002 Mr. Hufnagel opened the first Huf, a streetwear boutique that carried rare sneakers and apparel by brands like Supreme, in San Francisco. Huf had a minimalist interior design that highlighted its products, and the stores also displayed and sold works of art by skateboarders and artists like Aaron Rose and Haroshi.

In time Huf expanded to new locations and became catnip for sneakerheads, who waited in line for hours to spend hundreds of dollars on limited-release Nikes or Adidas.

Mr. Hufnagel designed some of those prized sneakers himself, including customized Nike Dunks, tie-dyed in the colors of the San Francisco Giants, and the Nike Air Max 90 HUFquakes, with a colorway that looked like a crackling fault line.

The store eventually developed into a label of its own, featuring apparel sometimes branded with a straightforward “H” logo and sometimes with more profane slogans. Huf apparel became known for irreverent T-shirts, capacious and durable pants and hoodies, and limited runs of products pegged to musical acts like Smashing Pumpkins, cartoon characters like Felix the Cat and products like Budweiser.

The company also made skate shoes for years, and supports a team of professional skateboarders. Mr. Hufnagel, of course, rode for his brand.

“Our clothing retails a bit higher than your average core skate brand, but our apparel winds up appealing to a broader spectrum of people,” Mr. Hufnagel told WWD in 2009. “We definitely take function into consideration, so you can skate in nearly anything we make, but you can wear what we make in a variety of elements outside of skating.”

Huf is now sold by major action-sports-themed retailers, like PacSun and Zumiez, and has stores in Los Angeles, New York and 16 locations in Japan. The company is currently owned by TSI Holdings.

Famous skateboarders the world over mourned Mr. Hufnagel’s death.

On his Facebook page, Tony Hawk called him “a skating legend” and “a pioneer DIY businessman that valued integrity over profits,” adding, “Skateboarding is collectively mourning today.”

Mr. Hufnagel was born in Manhattan on Jan. 21, 1974, to Monica and Robert Hufnagel. His mother was a nurse, and his father worked for Metropolitan Life Insurance. He got his first skateboard when he was 4 and took up the sport in earnest as a teenager.

He graduated from high school in 1992 and briefly attended San Francisco State University, but he dropped out after six months to become a professional skateboarder for Fun Skateboards. In 1993 he signed with Jim Thiebaud, a founder of Real Skateboards and an executive with Deluxe Distribution, which distributes Real and other skateboard hardware brands.

“Huf is a powerful skater and known as one of the highest olliers in the world,” Mr. Thiebaud told The San Francisco Chronicle in 2005, using the skateboarding term for jumping with the board. “He lands perfectly, and not in a gnarly, aggressive, attacking-the-streets way.”

Mr. Hufnagel met Ms. Freeman in the early 1990s. They married in 2001 and pooled their savings to open the first Huf store. Their marriage ended in divorce, but they remained close friends.

He is survived by his wife, Mariellen Hufnagel; their children; a brother, Chris; and his mother.

Mr. Hufnagel told The Guardian in 2011 that he was glad to see Huf grow without sacrificing its commitment to the subculture that started it.

“We always take care of the skateboarders,” he said, “but you have to think of the bigger picture because now you are selling to the world.”