This study presents quantified levels of phosphorylated metabolites in glandular tissue of human breast using 31P magnetic resonance spectroscopy at 7 T. We used a homebuilt 1H/31P radiofrequency coil to obtain artifact-free 31P MR spectra of glandular tissue of healthy females by deploying whole breast free induction decay (FID) detection with adiabatic excitation and outer volume suppression. Using progressive saturation, the estimated apparent T1 relaxation time of 31P spins of phosphocholine and phosphoethanolamine was 4.4 and 5.7 s, respectively. Quantitative measures for phosphocholine and phosphoethanolamine levels in glandular tissue were established based on MR imaging. We used a 3D 1H image of the breast to segment the glandular tissue; this was matched to a 3D 31P image of the B field of the 31P coil to correct for differences in glandular tissue volume and B1 inhomogeneity of the 31P coil. The 31P MR spectra were calibrated using a phantom with known concentration. Average levels of phosphocholine and phosphoethanolamine in 11 volunteers were 0.84 ± 0.21 mM and 1.18 ± 0.41 mM, respectively. In addition, data of three patients with breast cancer showed higher levels of phosphocholine and phosphoethanolamine compared with healthy volunteers. This may indicate a potential role for the use of 31P magnetic resonance spectroscopy for characterization, prognosis, and treatment monitoring in breast cancer. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.