Atrial fibrosis is considered to contribute to atrial fibrillation (AF) recurrence following cardioversion. This study tested the hypothesis that circulating levels of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) can predict AF recurrence postcardioversion. Precardioversion plasma samples (n = 82) were assayed for MMPs (eight types), TIMPs (all four types), N-terminus pro B-type natriuretic peptide, and high-sensitivity C-reactive protein levels. Patients were followed for AF recurrence postcardioversion. Despite 100 % restoration of sinus rhythm, 36 (44 %) reverted to AF within 3 months. Left atrial volume was increased in patients in whom AF recurred. Precardioversion MMP-9 was higher and TIMP-4 lower with AF recurrence. MMP-9, MMP-3, and TIMP-4 independently predicted AF recurrence. In multivariate analysis, combination of MMP-9, MMP-3, and TIMP-4 increased prediction of AF recurrence. Circulating levels of MMPs and TIMPs predict AF recurrence postcardioversion and may be used in a novel biomarker panel to guide AF stratification and therapy.