The estimate was in line with market expectations of operating profits between 8.14 trillion won and 8.63 trillion won for the January-March period at the world's largest mobile phone maker.
"The operating profits fell for two straight quarters year-on-year as profit margins in smartphones were falling and the growth rate in smartphone sales was decreasing due to growing competition," analyst Young Park of Hyundai Securities told AFP.
While the figure marks a 1.08 per cent increase on the previous quarter, it is 4.3 per cent lower than a year earlier, when the South Korean giant -- the world's largest technology firm by sales -- recorded operating profits of 8.78 trillion won.
The company said its first quarter sales were estimated at 53 trillion won, up 0.24 percent from a year earlier.
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Shares in Samsung fell 0.21 percent to close at 1.39 million won in a flat market.
Fixed first-quarter earnings are set to be announced later this month.
The figures come as growth in smartphone sales slow, with mature markets like North America and Europe near saturation.
This, coupled with the rapid expansion of smaller rivals like China's Huawei, has pressured Samsung to roll out cheaper handsets to woo consumers in emerging markets, especially China.
Nonetheless, estimated profits for Samsung's mobile division grew to 6.2 trillion won in Q1 of this year, up from 5.5 trillion won in the three previous months, Park said.
This follows the earlier-than-expected release of its latest Galaxy S5 smartphone -- which Samsung hopes will cement its lead in the global smartphone market -- in South Korea, analysts said.