Aims: Unlike most diagnostic procedures, the MitraClip® therapy requires precise positioning of transseptal access to ensure a successful procedure. Radiofrequency-based transseptal puncture has been developed to reduce complications and improve precision of septal access. We report our experience utilising surgical diathermy-based transseptal puncture for MitraClip implantation. Methods and results: Between October 2008 and April 2010, 72 patients underwent MitraClip therapy. Diathermy-assisted transseptal access was performed in 66 patients, under echocardiographic guidance, by manual contact of the diathermy blade with the Brockenbrough needle at the groin. Rate of successful puncture, time from femoral vein puncture to transseptal access and rate of complications were analysed. Diathermy-assisted puncture was successful in all cases. Time from femoral vein access to transseptal puncture was 16±19 min. There was one suboptimal septal puncture position (too low), and there was one coronary artery air embolism. There were no cases of intraprocedural pericardial effusion or arrhythmias. Conclusions: Surgical diathermy-based transseptal puncture may be a safe and effective alternative to either conventional or RF-based septal crossing. It improves precision of the septal access and may reduce the risk of bleeding complications. This technique is now routinely used at our institution for all MitraClip procedures.