This paper reports tissue distribution of vanadium in nonpregnant and pregnant Wistar rats. The experimental results showed that vanadium concentrations in nonpregnant rats were respectively from high to low: I. no treatment: ovary greater than uterus greater than kidney greater than lung greater than heart muscle greater than spleen greater than brain greater than liver greater than blood; II. 4h after single i.p. injection of V2O5 (5 mg/kg): kidney greater than ovary greater than liver greater than bone greater than uterus greater than lung greater than heart muscle greater than spleen greater than brain greater than blood. The results suggest that female genital organs are important organs in distribution of vanadium. The kidney is a main excretory organ. After 24h of treatment, a larger amount of vanadium in body has been excreted. Vanadium can pass through blood-brain barrier. Distribution of vanadium on gestation days 12 after 4h single i.p. injection of V2O5 (5 mg/kg) is: kidney greater than ovary greater than uterus greater than placenta greater than liver greater than fetus greater than bone greater than heart muscle greater than lung greater than brain greater than spleen greater than blood; on gestation days 16-18 after 4h single i.p. injection of V2O5 (5 mg/kg) is: kidney ovary greater than placenta greater than lung greater than bone greater than uterus greater than heart muscle greater than spleen greater than fetus greater than liver greater than brain greater than blood; after 24h (on gestation days 16-18) is: kidney greater than ovary greater than placenta greater than spleen greater than bone greater than lung greater than liver greater than fetus heart muscle greater than brain blood.(ABSTRACT TRUNCATED AT 250 WORDS)