Methods and systems involve multi-chamber cardiac capture detection utilizing sensing during a cross-chamber refractory period. First and second pacing pulses are delivered to first and second heart chamber. Capture or non-capture of the second heart chamber is determined. Sensing in the first heart chamber is performed to sense for cross-chamber propagation initiated by the second pacing pulse. Capture of the first chamber is detected if capture of the second heart chamber is detected and if the cross-chamber propagation is not detected.