A spectral analysis of human EDTA plasma from 124 different patients was undertaken using an FT-NIR spectrometer. Optimized intervals of the absorbance spectra were considered for the PLS-calibrations with reference concentrations from standard clinical methods determined in triplicate. The following relative prediction errors were achieved: total protein 1.4%, cholesterol 3.8%, triglycerides 8.6%, glucose 9.1%, and urea 18.6%.