A system and apparatus comprising a multi-sensor catheter for right heart and pulmonary artery catheterization is disclosed. The multi-sensor catheter comprises multi-lumen catheter tubing into which at least three optical pressure sensors, and their respective optical fibers, are inserted. The three optical pressure sensors are arranged within a distal end portion of the catheter, spaced apart lengthwise within the distal end portion for measuring pressure concurrently at each sensor location. The sensor locations are configured for placement of at least one sensor in each of the right atrium, the right ventricle and the pulmonary artery, for concurrent measurement of pressure at each sensor location. The sensor arrangement may further comprise an optical thermo-dilution sensor, and another lumen is provided for fluid injection for thermo-dilution measurements. The catheter may comprise an inflatable balloon tip and a guidewire lumen, and preferably has an outside diameter of 6 French or less.