The National Statistics Institute said the number of unemployed stood at 410,100, down from 422,000 in the previous quarter, while the total workforce was little changed at 5.2 million.
The share of unemployed young people fell to 21.9 percent in the first quarter from 23.5 percent in the last three months of 2017, and was the lowest mark since early 2011, when Portugal was hit by an economic and debt crisis. A year ago youth unemployment was 25.1 percent.
Portugal's economy grew at its fastest pace in ten years last year, sharply boosting employment. The jobless rate last year fell to 8.9 percent from 11.1 percent in 2016.