T1ρ mapping enables detecting early changes in the knee cartilage associated with osteoarthritis. Reproducible T1ρ measurements are challenging because of the motion artifacts arising from a long acquisition time of images at multiple spin-lock times. We implemented a new elastic motion correction method and applied it to T1ρ-weighted acquisitions in 20 subjects with normal knees and early osteoarthritis. The T1ρ voxel maps in articular cartilage generated from motion-corrected images showed significantly lower variability compared to maps derived from uncorrected images. The finding underscores the importance of motion correction in T1ρ mapping of the knee.