Background: Left atrial pressure (LAP) monitoring provides a useful option for management of hemodynamic status in pediatric open-heart surgical patients during the postoperative period. Patients and method: We used a triple-lumen catheter placed into the left atrium transseptally to measure left atrial pressure. Twenty children that were operated on in our clinic are included in this study: 11 males and nine females. A 5-Fr. triple-lumen radio-opaque polyethylene catheter was used for the procedure. After the repair of the primary cardiac defect, the distal end of the catheter was repositioned transseptally and advanced into the left atrium. The proximal and middle line's distal orifices were left in the right atrium. Distal line was used as a left atrial pressure line, the middle line as a central venous pressure line, and the proximal line as a route for fluid infusion or drug administration. Results: No mortality and no catheter-related complication were observed. No failure or complication occurred during withdrawal of the catheter. Conclusion: We conclude that this preliminary technique can be a useful and easy way of monitoring LAP, as well as providing central venous access.