The company posted earnings of 57 cents a share, narrowly topping Wall Street expectations, on net income of $3.4 billion. That compares to 41 cents a share and $2.5 billion from the same quarter in 2010.
Revenue rose 2.3 percent to $31.2 billion.
AT&T shares were up about 2 percent in premarket trading.
"We delivered another robust mobile broadband growth quarter for a very solid start to the year," Randall Stephenson, AT&T chairman and chief executive officer, said in a statement.
Though AT&T now must share rights to the Apple iPhone with Verizon, it saw a 10.2 percent growth in revenues, including an 8.6 percent increase in wireless service revenues.
It marked the company's best-ever first quarter increase in total subscribers, which rose 2 million to 97.5 million total.
The company also saw its best first-quarter smartphone sales, with more than 5.5 million units sold, and an increase of one million annualized in iPhone activations.