Relatively few studies have assessed the relationship between dietary intakes and survival after breast cancer diagnosis. We investigated the influence of diet, including dietary fat (percentage energy), fiber, vegetable, and fruit intakes, and micronutrients (folate, carotenoids, and vitamin C) on overall survival in women diagnosed with breast cancer. Subjects were postmenopausal women diagnosed with breast cancer (N = 516) between 1994 and 1995 with a mean survival time of 80 mo (SD: 18). Subjects completed a food frequency questionnaire for the year prior to diagnosis. Cox proportional hazards models were used to measure the relationship between dietary intakes and death due to any cause after breast cancer diagnosis. In the multivariate analysis, we found that the hazard ratio [HR and 95% confidence interval (CI)] of dying in the highest tertile compared to the lowest tertile of total fat, fiber, vegetable, and fruit was 3.12 (95% CI = 1.79-5.44), 0.48 (95% CI = 0.27-0.86), 0.57 (95% CI = 0.35-0.94), and 0.63 (95% CI = 0.38-1.05), respectively (P <or= 0.05 for trend, except for fruit intake). Other nutrients including folate, vitamin C, and carotenoid intakes were also significantly associated with reduced mortality (P <or= 0.05 for trend). These results suggest that in postmenopausal women diagnosed with breast cancer, reduced dietary fat and increased fiber, vegetable, fruit, and other nutrient intakes associated with a plant-based, high-fiber diet improves overall survival after breast cancer diagnosis.