We developed a multi-slice free-breathing volumetric GRE cine imaging sequence for generating a 3D peak strain map for the left atrium. The sequence uses interleaved radial acquisition and a novel multi-band self-gating technique, accelerated with UNFOLD, and parallel imaging. The method was validated in 8 healthy subjects against alternative motion-correction methods. The results showed a stable performance using multi-band self-gating, and a sufficient image quality to generate a 3D strain map using feature tracking. This method provides a novel approach to interrogate the relationship between left atrial fibrosis, quantified by 3D left atrial gadolinium enhancement, and left atrial strain.