Net profit for the world's second-largest chipmaker amounted to 674 billion won ($658 million) for April to June, down 29 percent from a year ago.
Operating profit inched down three percent to 1.08 trillion won during the same period, the Icheon-based company said in a statement.
Sales remained nearly unchanged at 3.92 trillion won.
Hynix said the average selling price of its dynamic random access memory (DRAM) chips, mostly used for computers, fell five percent in the second quarter.
The average price of its NAND flash chips -- used for mobile devices -- also dropped 19 percent although production increased 54 percent.
Global demand for memory chips is expected to grow later this year in emerging markets including China, it said.
Chipmakers are also expected to keep production minimal to ward off a glut that hurt their businesses earlier this year, a combination that will help boost prices later, the company said.