Abstract Hypoalbuminemia, a frailty criterion, belongs to a group of comorbidities not captured as a traditional risk factor. We assessed its prognostic value in patients who underwent transcatheter aortic valve implantation (TAVI). The study included 1215 consecutive patients from the Optimized CathEter vAlvular iNtervention (OCEAN)-TAVI Japanese multicenter registry. Hypoalbuminemia was defined as serum albumin level<3.5 g/dL. Baseline characteristics, procedural outcomes, and all-cause, cardiovascular, and non-cardiovascular mortality rates after TAVI were compared between patients with albumin level<3.5 g/dL (hypoh-ALB group, n=284) and those with albumin level>3.5 g/dL (nonhyponh-ALB group, n=931). Several baseline characteristics differed significantly between both groups, including age (85.1±5.1 years vs. 84.2±4.9 years, p=0.012), ejection fraction (58.5±14.3% vs. 62.9±12.4%, p<0.001), baseline kidney function, or liver disease. The 30-day mortality rate in all patients showed significant differences between the 2 groups (3.9% vs. 1.3%, p=0.005). During a mean follow-up of 330 days, cumulative all-cause, cardiovascular, and non-cardiovascular mortality rates were significantly higher in the hALB group than in the nhALB group (log-rank test, p<0.001, p=0.0021, and p<0.001, respectively). The groups were also analysed using a propensity-matching model for adjusting the baseline differences. The analysis revealed that the poorer prognosis of the hALB group in terms of cumulative all-cause and non-cardiovascular mortality was retained (p=0.038, and p=0.0068, respectively); however, differences in cardiovascular mortality rates in the two groups were attenuated (p=0.93). In conclusion, hypoalbuminemia was associated with poor prognosis, highlighted by the increase in non-cardiovascular mortality. Baseline albumin level could be a useful marker for risk stratification before TAVI.