Gross average salary increased by a similar percentage to RON2,395, the data showed.
One-time bonuses, including Easter bonuses, had little influence on the wage evolution in April, INS said.
Staff in the financial sector received the highest salary raise in April (up by 22.8% from March), while Romanians working in the mining industry received 19.5% more money compared with the previous month.
At the opposite end, employees in the tobacco industry saw the biggest monthly decline in their salaries, of 51.4%.
In April compared with the year-earlier month, Romanian average net salary rose 4.5% in nominal terms. (EUR1=RON4.3964)