For the first time in more than two years, Samsung's quarterly net profit declined from the previous quarter, the South Korean electronics powerhouse said.
Today's news came amid deepening concerns about slowing growth in smartphone markets.
The maker of the Galaxy smartphone said that its net earnings for the October-December period fell 11% from the third quarter to 7.3 trillion won ($4 billion).
It is the first time in nine quarters that profit did not grow from the previous quarter.
Compared to a year earlier, net earnings inched up 4%. The results fell short of market expectations. Analysts polled by FactSet expected earnings of 7.5 trillion won.
Samsung Electronics blamed the strong won, high marketing costs to promote Galaxy devices and other one-time expenses, such as special bonuses to employees.
The weaker-than-expected earnings raised speculation that Samsung's profit growth could come to halt. The company is the world's largest smartphone supplier and competes with Apple.
Quarterly sales were essentially unchanged from the previous quarter and up 6% over a year earlier.
Robert Yi, head of investor relations, said it would be difficult for the company to improve earnings during the first quarter of this year as display panels and TV businesses would probably be weak.
He predicted that capital spending would be at a similar level as 2013.