Introduction To investigate the relation between left atrial (LA) volume, sphericity, and fibrotic content derived from contrast‐enhanced cardiac magnetic resonance imaging (CE‐CMR) and their impact on the outcome of catheter ablation for atrial fibrillation (AF). Methods and results In 83 patients undergoing catheter ablation for AF, CE‐CMR was used to assess LA volume, sphericity, and fibrosis. There was a significant correlation between LA volume and sphericity (R  =  0.535, P < 0.001) and between LA volume and fibrosis (R  =  0.241, P  =  0.029). Multivariate analyses demonstrated that LA volume was the strongest independent predictor of AF recurrence after catheter ablation (1.019, P  =  0.018). Conclusion LA volume, sphericity, and fibrosis were closely related; however, LA volume was the strongest predictor of AF recurrence after catheter ablation.