Background: Diet has been implicated in prostate cancer risk and there is evidence of risk reduction with a healthy diet. The objective of this population-based case control study was to examine whether a low fat diet rich in fruits and vegetables can reduce the risk of developing prostate cancer in Mumbai, India. Methods: Included in this study were microscopically proved cases of prostate cancer diagnosed during 1998 to 2000 and registered by Bombay Population Based Cancer Registry (n=594). The controls were healthy men belonging to the resident general population of Mumbai, India. Two controls for each case matched by age and place of residence were selected as the comparison group. Data on oil/fat consumption, fruits and vegetable consumption and other probable confounding factors were obtained by structured face-to-face interview. After exclusions, 390 cases and 780 controls were available for final analysis and confounding was controlled by multiple logistic regression. Results: 58.7% of the control group consumed more than 3 kg of fruits and vegetables per week compared to 52.1% of the case group. Controlling for age and probable confounding factors, a statistically significant protective effect for prostate cancer was observed for those who consumed fruits and vegetables 2 to 3 kg (OR 0.5, 95%CI 0.3-0.8) and more than 3 kg (OR 0.4, 95% CI 0.3-0.6) per week compared to those who consumed less than 2 kg per week. The linear trend for the protective effect was highly significant with increase in the consumption of fruits and vegetables (p = 0.001). Even though not statistically significant, oil/fat consumption showed an elevated risk (OR 1.7, 95%CI 0.9-3.3) for those who consumed more than 2kg of oil/fat per month compared to those who consumed less than 1kg. Conclusion: The findings from this study support the hypothesis that a low fat diet rich in fruits and vegetables may reduce the risk of prostate cancer.