A total of 244,437 applications were filed, up 3.7 per cent on 2010.
The Office takes applications from 38 European states, including Croatia, and approves four in ten on average. Last year, it approved 62,115 patent applications, 6.9 per cent more than in 2010.
Germany led the way with 33,181 applications filed, followed by France with 12,107 and Switzerland with 7,786.
Croatia filed 56 patent applications in 2011, four more than in 2010.
Sixty-two per cent of the applications in EPO came from outside of Europe, of which one-fourth from the US. China and South Korea made up 32 per cent of last year's applications, with China filing 16,946 as against only 160 in 2000.
Broken down by company, Siemens was the top-ranking with 2,235 applications, followed by the Dutch Philips and the Korean Samsung.