Proton 3D MR spectroscopic imaging (MRSI) provides spatial metabolic information of the prostate for improved cancer detection, localization, and staging. Clinical application of MRSI of prostate requires automatic quality control of spectra. We propose Qratio, a ratio balancing constructive spectral components of choline and citrate signals with destructive elements of lipid signals, water residuals and noise. We demonstrate that Qratio can serve as a general, fast and automated tool for quality control of prostate MRSI data, independent of field strength (1.5-7T) and acquisition protocol. The Qratio can be displayed as maps and performs with an accuracy of 88±3% and AUC=0.93.