The objective of this study was to examine serum concentrations of alpha-carotene, beta-carotene, lutein, lycopene, and beta-cryptoxanthin due to consumption of vegetable juice versus raw or cooked vegetables. Subjects included female breast cancer patients who had undergone surgical resection and who were enrolled in a feasibility study for a trial examining the influence of diet on breast cancer recurrence. A high-vegetable, low-fat diet was the focus of the intervention, and some of the subjects were specifically encouraged to consume vegetable juice. At 12 months, blood samples were collected and analyzed for carotenoid concentrations via high-performance liquid chromatography methodology. Matched analysis and paired t test were conducted on two groups: those who consumed vegetable juice (the juice group) and those who consumed raw or cooked vegetables (no juice group). Serum concentrations of alpha-carotene and lutein were significantly higher in the vegetable juice group than in the raw or cooked vegetable group (P < 0.05 and P = 0.05, respectively). Paired t test analysis did not demonstrate a significant difference in serum values of beta-carotene, lycopene, and beta-cryptoxanthin between subjects consuming juice and those not consuming any juice. These results suggest that alpha-carotene and lutein appear to be more bioavailable in the juice form than in raw or cooked vegetables. Therefore, the food form consumed may contribute to the variability in serum carotenoid response to vegetable and fruit interventions in clinical studies.