The social network site made a profit of $64m (£41m) in the final three months of 2012, compared with $302m a year earlier.
Revenue was up 40% at $1.6bn, largely due to a big jump in advertising revenue, a quarter of which came from mobile platforms.
Shares in Facebook fell by almost 6% in after-hours trading in New York. The shares launched on the Nasdaq stock exchange in May at $38, and had halved in value by September.
They have since recovered to stand at $31 at the close of trading on Wednesday. The drop in after-hours trading suggests the shares will fall back again when full trading resumes on Thursday.
"Mobile revenue was expected to be a little higher," said analyst Aaron Kessler at Raymond James. "Overall it's a solid quarter but maybe [the company has suffered from] high expectations going into the quarter."
Revenue from advertising was $1.3bn, 41% up on a year earlier.
Source: BBC News
