"If you are the Fed, and you see what CEO Fred Smith had to say, you would say, 'I don't know. How much do we have to cut to make his core business better?'" Cramer said in a "" interview.
The package-delivery giant posted fiscal first-quarter earnings per share of $2.42 on revenue of $12.3 billion. The company had been expected to report profit of $2.46 a share and revenue of $12.3 billion.
FedEx also lowered its fiscal-year guidance, citing the strength of the U.S. dollar.
The Fed kicked off its two-day meeting Wednesday and is expected to announce a decision on interest rates Thursday at 2 p.m.
"The companies [with] fundamentals that are declining are indicative of the fact that there is slowing throughout the chain," Cramer added. "Those people who say we are ready for a Fed rate hike … don't bother what companies like FedEx have to say. This FedEx [news] is bad."
The company's shares were down more than 3 percent midmorning.
Disclosure: Cramer's trust did not own FDX stock when this article was published.