The objective of our study was to evaluate a new commercially available method of MRI-guided vacuum-assisted breast biopsy using an open coil and a closed 1.5-T scanner. Consecutive MRI-guided vacuum-assisted breast biopsies of 38 lesions in 28 women performed between May and September 2003 at two practice sites in the United States were retrospectively reviewed. Lesion characteristics including size, morphology, and enhancement were recorded. Times to perform each procedure, defined as the time from the start of the first localizing scan to the final scan after biopsy, were recorded. Histologic results for all lesions were obtained, and surgical, imaging, or clinical follow-up was performed. Enhancing masses and foci ranged from 2.5 to 19 mm. Nonmasslike enhancements ranged from 6 to 70 mm. All 38 biopsies (100%) were technically successful, and no complications were associated with any of the biopsy procedures. The average time to perform the 19 single-site MRI-guided procedures was 38 min (range, 23-57 min). The 11 multiple-site biopsies performed in a single breast averaged 59 min (range, 51-68 min), and eight bilateral biopsies averaged 64 min (range, 46-80 min). Histologic results from vacuum-assisted breast biopsy revealed malignancy in 14 lesions (37%), atypical ductal hyperplasia in two lesions (5%), and benign findings in 22 lesions (58%). One of two lesions with atypical ductal hyperplasia was upgraded to ductal carcinoma in situ after surgery, for an overall cancer yield of 40% (15/38). This new method of MRI-guided vacuum-assisted breast biopsy is a safe, effective, and time-efficient means of MRI-guided tissue sampling.