The world's number three shipbuilder by sales said in a statement that its net profit for the three months ended June 30 declined to 170.1 billion won ($162 million) from 176.5 billion won a year earlier.
Sales rose 13 percent to 3.178 trillion won from 2.823 trillion won.
Operating profit more than tripled to 339.9 billion won in the April-June quarter from 106.9 billion won a year earlier.
Orders for high-end ships such as container carriers and liquefied natural gas carriers helped boost the operating profit, said company spokesman Yoon Yo-Han.
Daewoo Shipbuilding achieved 65 percent of its annual order target of $11 billion in the first six months.