Over the past several years numerous attempts have been made to treat atrial fibrillation surgically. The most effective of all such surgical treatments has been the Maze operation, developed by James Cox in the 1980s. The Maze operation has demonstrated excellent long-term results. The procedure is based on a complex surgical technique, thus is it not easily being reproduced by every surgeon. Different attempts have been made to simplify the original Maze technique. In 1999, the electrophysiologists at the authors' institution outlined a lesion concept for left atrial ablation in the treatment of atrial fibrillation. In 387 patients, the authors used intraoperative radiofrequency ablation to cure AF. The results were comparable to the maze procedure. This concept was very effective but after a time period of 4 years in 1% of patients esophagus perforations occurred. In a quest to identify other energy sources to produce good ablation results with less possible complications, intraoperative cryoablation has been developed. In the following study conducted the authors were able to use a new flexible cryocatheter (Cryocath Surgifrost). Sinus rhythm was achieved in 71% after a 1 year follow-up period with low morbidity and comparable mortality, which was due to the concomitant cardiac pathologies and operative procedures. In conclusion, thus far from this series of patients presented, the authors have demonstrated that cryoablation with Argon-cryotechnology is efficacious and safe.