Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) is a life-threatening condition caused by the deposition of amyloid fibrils from misfolded transthyretin in the myocardium. While protein misfolding underlies its pathogenesis, the triggers and factors driving disease progression remain unclear. This study explores the relationship between lifestyle factors, particularly oxidative stress, and the incidence of ATTRwt-CA. A lifestyle questionnaire survey was conducted among patients with and without ATTRwt-CA at Kochi Medical School Hospital, Japan. Multivariate regression models were used to assess the odds of ATTRwt-CA occurrence in individuals with identified risk factors. The mean ages of patients in the ATTRwt-CA group (n = 65) and the non-ATTRwt-CA group (n = 65) were 77.9 ± 6.5 years and 78.5 ± 7.4 years, respectively. Multiple logistic regression analysis identified male sex (adjusted odds ratio, 4.35; 95% confidence interval, 1.39-14.29; P = 0.01) as an independent risk factor for ATTRwt-CA. Past sunlight exposure of ≥ 1 hour per day (adjusted odds ratio, 3.21; 95% confidence interval, 0.87-11.88; P = 0.08) showed a tendency towards a positive association with ATTRwt-CA occurrence. In contrast, past black tea consumption (adjusted odds ratio, 0.13; 95% confidence interval, 0.01-1.28; P = 0.08) and past smoking (adjusted odds ratio, 0.29; 95% confidence interval, 0.12-0.72; P < 0.01) were tentatively or significantly associated with ATTRwt-CA occurrence. Lifestyle factors may be linked to the occurrence of ATTRwt-CA, potentially through mechanisms involving oxidative stress.