The intrinsic optical parameters absorption coefficient , scattering coefficient , anisotropy factor , and effective scattering coefficient were determined for human red blood cell (RBC) suspensions of hematocrit 33.2% dependent on the oxygen saturation (SAT ) in the wavelength range , including the range above , about which there are no data available in the literature. Integrating sphere measurements of light transmittance and reflectance in combination with inverse Monte Carlo simulation were carried out for SAT levels of 100 and 0%. In the wavelength range up to , the absorption behavior is determined by the hemoglobin absorption. The spectral range above the cells’ absorption shows no dependence on SAT and approximates the absorption of water with values 20 to 30% below the respective values for water. Parameters and are significantly influenced by the SAT -induced absorption changes. Above , decreases continuously from values of to values of at . The anisotropy factor shows a slight decrease with wavelengths above . In the spectral regions of 1450 and where water has local absorption maxima, shows a significant decrease down to 0.85, whereas increases.