Ms Larriva's 17-year-old daughter, who was with her in one of the helicopters, and five army officers also died.
The aircraft collided during a night-time exercise near the city of Manta on the Pacific coast.
Ms Larriva, 50, took office on 15 January, and was the first woman to serve as Ecuador's defence minister.
Ms Larriva, who formerly headed the small Socialist party, was appointed by left-wing President Rafael Correa when he came to power earlier this month.
Mr Correa expressed sorrow over the accident after travelling to the crash site.
He said country was living through a very difficult moment.
"We are going to ask friendly countries to help us with the investigation of the accident," the president added.
Mr Rafael Correa, a left-wing economist, won Ecuador's presidential election in November and was inaugurated last week.