Proton magnetic resonance spectroscopy (¹H MRS) has demonstrated its abilities to detect an increase of choline containing compounds (Cho) in various brain tumors and prostatic cancer tissues. Based on preclinical works done by other authors using multinuclei MRS, it is reasonable to assume malignant breast tumors will have elevated level of Cho compared to that of normal, tissues and benign breast lesions. Several challenges must be met to obtain clinically useful ¹H breast spectrum. Good water and fat suppression, Bo homogeneity are required to detect low level metabolic signals like choline if any. In this study, we investigated the clinical utility of ¹H MRS with simultaneous suppression of water and fat signals, using breast imaging surface coil for evaluating breast cancer with small lesions. All studies were performed using a GE signa MRI unit (1.5 T, Ver 5.5) and 2-channel breast coil (GE). Water suppression was achieved by chemical selective saturation, and fat signal was attenuated using inversion recovery sequence. Spectroscopic data were acquired with PRESS sequence. Twenty-three patients, age 14-75, were examined. Eleven of these patients presented with invasive ductal carcinoma. The remaining patients presented with benign processes including fibroadenoma, fibrocystic change, galactocele. adenosis, ductal ectasia and dystrophic calcification. The size of lesions were variable (8-90 mm in diameter). Choline at 3.25 ppm was visible in the spectra of all cancer patients. while invisible in the spectra of all benign lesions except a lesion of dystrophic calcification. We concluded that in vivo detection of choline containing compounds in breast carcinomas using proton magnetic resonance spectroscopy demonstrated its potential as a noninvasive tool for differential diagnosis of malignant and benign breast lesions larger than 7 mm in diameter.