The effects of laser irradiation on the absorption coefficients of the normal and anemic human blood samples were investigated. Two continuous wave (CW) diode-pumped solid-state lasers (DPSSLs) of different wavelengths,532 nm and 671 nm, were used. The output power of these lasers can be adjusted over the range 0-100 mW. In the present study, the output power of both lasers was fixed at 20 mW. The blood samples were irradiated at different irradiation times, 5, 15, and 30 min. The absorption coefficients of the normal and anemic human blood samples were determined from the measurements of the absorbance spectra of the unirradiated and irradiated samples. The absorbance spectra were measured using UV-Visible double-beam spectrophotometer operating over the wavelength range 190-1100 nm. Significant changes in the absorption coefficients of the irradiated blood samples were observed compared to the unirradiated blood samples. The results obtained in the present investigation showed that there are significant effects of laser irradiation on the optical properties of the human blood samples. These effects can result in noticeable changes in their absorption coefficients. The results suggested that the technique used in the present investigation has great potential to be a useful tool for the clinical diagnostics and the medical applications.