Direct oral anticoagulant (DOAC) dose adjustment is based on age, renal function, and body weight. There is a paucity of data describing the factors associated with the prescription of inappropriate dosage and their impact on clinical outcomes among patients receiving transcatheter aortic valve implantation (TAVI). In a single-center study, 432 patients who were on long-term DOAC therapy and underwent TAVI between 2015 and 2022 were included. We analyzed the predictors and outcomes of inappropriate dosing of DOACs; namely apixaban, dabigatran, edoxaban, and rivaroxaban. A composite endpoint, including all-cause mortality, life-threatening/major bleeding, stroke, peripheral thromboembolic complications, or myocardial infarction, was assessed after 1 year. In this TAVI cohort, inappropriate DOAC dosing was observed in 20.6% of patients. Inappropriate DOAC dosage was related to female gender (adj. odds ratio [OR] 2.72, 95% confidence interval [CI] 1.64-4.51, p < 0.001) as well as lower estimated glomerular filtration rate (eGFR) (adj. OR 0.99, 95% CI 0.98-1.00, p = 0.019), and to the administration of non-rivaroxaban DOACs (adj. OR 0.28, 95% CI 0.16-0.50, p < 0.001). After 1 year, patients on both appropriate and inappropriate DOAC dosage exhibited comparable rates of the composite endpoint (OR 0.88, 95% CI 0.53-1.46, p = 0.622). Old age (adj. OR 1.05, 95% CI 1.01-1.10, p = 0.018) as well as anemia (adj. OR 0.86, 95% CI 0.75-0.99, p = 0.031) emerged as independent predictors of the composite endpoint. In this TAVI cohort, female gender and renal insufficiency were associated with inappropriate DOAC dosage, whereas rivaroxaban was linked to appropriate dosing. Inadequate DOAC dosage did not translate into a worse outcome in our TAVI population. Prospective Segeberg TAVI Registry (ClinicalTrials.gov identifier: NCT03192774).