This is an observational prospective study for evaluation of the value of Three Dimensional Power Doppler Ultrasonography in differentiating between Adenomyosis and Uterine Leiomyoma. It was carried on 60 patients in the age group between 20 - 60 yrs., who were previously diagnosed by two dimensional ultrasonography to have adenomyosis or leiomyoma . Three dimensional power doppler ultrasound is performed before surgery(myomectomy or hysterectomy). The examination evaluated, vascular location (location), vascular index (VI), flow index (FI), and vascular-flow index (VFI). Postoperatiive histopathological examination was done to confirm the diagnosis. Statistical analysis of the results revealed that patients with uterine leiomyoma had significantly higher VI (p= 0.005) , FI (p = 0.000), and VFI (p =0.004) levels than did patients with adenomyosis. A significant difference in vascular location was also noted between cases of uterine leiomyoma and adenomyosis (Fisher exact test, p = 0.000). The results suggest that 3D power Doppler ultrasonography could be used to more effectively differentiate between uterine adenomyosis and leiomyoma