The 64-year-old singer told BBC 6 Music he was "a little bit spoiled" by working with Lennon at the start of his career.
"I'm a little bit wary of collaborating with other people because it doesn't happen as easily or as amazingly as it did with John," he said.
McCartney and Lennon started their partnership when they were teenagers in Liverpool, England, and went on to be considered one of the most successful songwriting partnerships ever.
"It's a funny subject, the collaboration thing, because I collaborated with John and you're a little bit spoiled after that," he said. "That was one hell of a collaboration."