Recent progress in spectroscopy and chemometrics have brought the reagentless analysis of blood substrates by near infrared spectroscopy into clinical reach. Results for the in-vitro analysis of several blood substrates in human blood plasma using multivariate calibration by partial-least squares are presented for 125 hospital samples. Whereas the relative mean-squared prediction error for total protein (1.4%) using short wave NIR data is comparable with previous results using conventional NIR spectroscopy, the errors found for total cholesterol (6.5%) and triglycerides (13.8%) are nearly a factor of two worse for this study.