"Is Telsa overvalued? If they make 500,000 cars, no," Cramer said on "Squawk on the Street."
On Tuesday, the company's stock went above $300 a share for the first time ever.
Tesla said it delivered just more than 25,000 vehicles in the first quarter. That's a 69 percent increase from last year and edging past Goldman Sachs' forecast of 23,500 vehicles.
The carmaker is on track to meet or beat expectations for the first half of 2017, according to analysts, as it moves closer to beginning production on its Model 3 Sedan later this year.
"Telsa is a loved car, and people buy the stock, Cramer said.
Shortly after the news Monday, Walt Mossberg, executive editor and columnist at The Verge, tweeted that he admired the luxury electric car company but said, "stock market valuations don't reflect reality."
Musk fired back in a tweet, saying "Tesla is absurdly overvalued if based on the past, but that's irrelevant. A stock price represents risk-adjusted future cash flows."
In a tweet Monday, Musk mocked short sellers of the company's stock after the better-than-expected deliveries news.
— CNBC's Robert Ferris and Reuters contributed to this report.