Played at the ITC Stella Maris in Umag, Croatia, the semi finals matched number four seed Marcel Granollers (ESP) against number one seed Fernando Verdasco (ESP), and number two seed Marin Cilic (CRO) against number three seed Alexander Dolgopolov (UKR).
Granollers and Verdasco met once in the past year in the finals of the 2011 Swiss Open with Granollers winning. Cilic and Dolgopolov met once in the past year in the finals of this same Croatia Open tournament in 2011 with Dolgopolov winning.
In advancing to the semi finals, Granollers defeated Potito Starace and Matthias Bachinger; Verdasco defeated Ernests Gulbis and Andrey Kuzentsov; Cilic defeated Daniel Brands and Wayne Odesnik; and Dolgopolov defeated Fabio Fognini and Carlos Berlocq.
On the clay surface of the ITC Stella Maris, the semi final results were: Granollers d. Verdasco 6-2, 6-7(5),
6-1, and Cilic d. Dolgopolov 7-5, 6-2.
With the semi final win, Cilic became the first Croat in 22 years to play in the finals of the Croatia Open.