The group said it carried 2.8 million passengers between the UK and the continent in the three months to the end of June – the highest ever in one quarter.
Its record performance came in spite of the Channel Tunnel and ferry disruption seen late last month, when striking Calais ferry workers closed the French port and blocked Eurotunnel rail services.
Eurostar said a boost from business travellers and strong take-up of its new south of France service drove the record number of passengers, which marked a 3 per cent rise year-on-year.
The group saw Business Premier passenger numbers leap 10 per cent higher in the three months, with an increase reported on both sides of the channel.
It has already sold more than 88,000 tickets for its new south of France service, which was launched on May 1 and stops at Lyon, Avignon and Marseille.
It has already increased the service from three times a week to five. Second quarter revenues rose by 1.5 per cent to £232m after the buoyant demand, according to Eurostar.
But despite the second quarter boost, Eurostar said half-year revenues overall were 2 per cent lower after a hit in the first three months by a lorry fire that closed the Channel Tunnel, and Paris terrorist attacks in January.
Large movements in foreign exchange rates also had an impact on sales and the group said with this stripped out, half year revenues were 4 per cent higher.