The world's biggest smartphone and memory chip maker said operating profit fell 56% from a year earlier.
The results reflect a broader industry slowdown, weighed down by the US-China trade war.
The firm also faces more possible disruption to its chip business due to a trade row between Seoul and Tokyo.
The South Korean firm posted operating profit of 6.6 trillion Korean won ($5.6bn; £4.6bn) for the three months to June, a 56% drop from the 14.87 trillion Korean won posted in the same period a year earlier. The result was in line with company estimates.