Ryanair says it saw its traffic fall by 48% in March due to the coronavirus pandemic.
Statistics released by the airline show it dropped by 48% to 5.7 million guests last month due to flight bans and restrictions.
Ryanair says it operated more than 33,000 scheduled flights last month, but it had budgeted for 64,000.
This included a number of rescue and medical flights on behalf of various European Union governments.
But the carrier says that due to widespread EU flight bans and restrictions, it expects to carry "minimal if any traffic" during the months of April and May.
Earlier this week, Ryanair said over 90% of its aircraft are grounded for the coming weeks because of flight bans or other restrictions.