The economy grew by 0.8pc compared to the previous quarter, slightly above the rise of 0.7pc in the last quarter of 2018.
Meanwhile, the Ministry of Finance said tax inflows rose by 6.5pc year-on-year in the first four months of the year while spending on public sector wages rose by as much as 9.4pc after the government agreed with trade unions to raise them.
As a consequence Slovenia ran a budget deficit of 5.2 million euros ($5.8 million) in the first four months, versus a surplus of 26.6 million euros in the same period of 2018.
Nevertheless, the government plans to end 2019 with a budget surplus of about 0.8pc of GDP, versus a 2018, surplus of 0.7pc .
Analysts said strong export growth and domestic spending backed government expectations that GDP will rise by 3.4pc this year, versus 4.5pc in 2018.
Exports rose by 7.6pc year-on-year in the first quarter versus a rise of 6.8pc in the last quarter of 2018. General government spending was up by 3.6pc year-on-year and household spending rose by 2.6pc .
"Export growth remains high and household spending is expected to continue rising due to high employment and recent wage increases," Iztok Trobec from Dezelna Banka told Reuters.
Risks that could reduce growth include economic slowdown in the rest of the European Union, which includes Slovenia's main trading partners, and a trade war between the United States and China that could indirectly hurt Slovenian exports, he added.
Slovenia exports about 80pc of its production, mainly to other EU states.
Its main exports include cars, car parts, pharmaceuticals and household appliances.