The airlines said on March 1 that it increased its flights between Tehran and Abu Dhabi from 10 to 14 flights a week.
Earlier in October, the UAE airlines increased its flights between the two capitals from seven to ten flights a week.
Etihad Airways began flights to Tehran in 2006.
Following a nuclear deal Iran reached with world powers last year, many world airlines resumed flights to Iran or increased flights to the country.
More than 30 airlines from European and Asian countries have currently direct flights to Tehran's Imam Khomeini International Airport.