Samsung profits have been hit by falling sales for its smartphones and semiconductors.
The “difficult business environment and slowing IT demand” sent net profit for Q4 of 2015 down by 40% to 3.2 trillion won ($2.7 billion).
The tech giant warned it would be difficult to maintain profits this year at the same level as 2015.
Samsung revenue for 2015 fell 5.6 trillion won to 200.6 trillion won ($165.5 billion) compared with the previous 12 months.
The Galaxy S6, the most recent top-of-the-range handset launched in April 2015, failed to excite consumers and the company has struggled to maintain market share.
Samsung forecast single-digit percentage growth in both smartphone and tablet sales amid “softening demand and intensifying competition”.
“Despite this challenging environment, the company will focus on increasing smartphone shipments and maintaining a double-digit margin through releases of competitive devices,” Samsung said in a statement.
Samsung’s other core business, semiconductors, has also met headwinds following weaker demand for personal computers.
The company makes components for the iPhone, which is itself facing a slowdown in sales.
Apple said on January 26 it expected to report the first year-on-year decline in iPhone sales in the current quarter.
Samsung Electronics shares fell 2% in Seoul.