Apple saw record profits, up 57%, in the three months to the end of December, lifted by demand for its Mac computers and iPhones.
Some analysts fear that the slowing US economy could weigh on Apple
Sales of its iPhone, released in June last year, reached 2.3 million and lifted its earnings to $1.58bn (£806m), up from $1bn a year ago.
But the firm forecast earnings for the next three months that were less than the market expected.
The news will fan fears over the extent of a US consumer slowdown.
Apple shares shed 3.5% at $155.64 and are expected to fall further when trading opens in New York on Wednesday.
Apple said it shipped 2.3 million Macintosh computers, 44% more than the year before.
In addition, the firm sold 22 million iPods during the period, beating its previous record set during the 2006 Christmas season.
Apple is considered a bellwether in the technology sector
"We're thrilled to report our best quarter ever, with the highest revenue and earnings in Apple's history," said Steve Jobs, Apple's chief executive.
But some analysts considered that Apple's earnings could have peaked for the time being.
"Consumers right now are wary of the economy," said Tim Bajarin, head of consultancy Creative Strategies
"They are really reluctant to pull the financial trigger on any purchases outside of their normal daily expenses."
Apple is betting future profit growth will come from new products, including online film rentals for iTunes users and the world's thinnest laptop Mac Book Air.