IRNA says the Guardian Council today approved election results of 207 constituencies, including Tehran, where a reformist-moderate bloc won all 30 seats of the city in the house.
In February, reformists and moderate allies of President Hassan Rouhani won the majority in voting for the 290-member assembly and a clerical body charged with choosing the country's next supreme leader.
Iran is to hold runoff elections for nearly a quarter of the seats in parliament on April 29.
The results were seen as a major setback for hard-liners opposed to the landmark nuclear deal reached with world powers last year, which lifted international sanctions in exchange for Iran curbing its nuclear activities.