Abstract Background While Atrial fibrillation is considered a risk factor for tricuspid regurgitation (TR), prospective long term data in the field is lacking. This analysis aimed to identify risk factors of TR progression during a decade of follow up among patients with and without AF. Methods Patients with full echocardiographic and clinical follow of at least 5 years were included. Individuals presenting with significant TR at baseline were excluded. Patients were divided into two groups based on baseline diagnosis of AF, followed by stratification according to systolic pulmonary artery pressure (sPAP). The primary outcome was the occurrence of new significant TR (≥ Moderate). Results Study population included 15,957 patients with a median age of 63 (IQR: 54-72) of whom 6,068 (38%) were women and 1,837 (11.5%) had baseline AF. During a median follow-up period of 11 years (8.5 – 13.5), 1,191 (7.5%) patients developed significant TR. Compared with sinus rhythm, patients with AF were 4 and 2 times more likely to develop significant TR during follow up in a univariate and multivariate models, respectively (95% CI 3.66 - 4.68 and 1.98 – 2.56, p < 0.001 for both). Older age, female sex, chronic kidney disease (CKD), left heart disease (LHD) and impaired right ventricular (RV) function, rate control and permanent AF were all risk factors for TR progression. The association of baseline AF with TR during follow up was sPAP – dependent, such that among patients with normal sPAP AF associated risk was high while among patients with high baseline sPAP AF-associated risk was significantly lower (HR 2.87 vs. 1.77; p for interaction < 0.001). Competing risk analysis with death as competing event yielded consisted results. Conclusions Baseline AF is a strong and independent risk factor for TR development. This association is more pronounced among patients with normal pulmonary arterial pressures, emphasizing the need for focused research on preventing TR development in this population.