Photothermal radiometry (PTR) is shown to yield optical absorption spectra in the visible region of untreated and strongly scattering material, using Nd2O3powder, blood, and a green leaf as test samples. A conventional high pressure Xe lamp/monochromator combination was employed for illumination at power levels below 1 mW, with a PbSnTe infrared detector for recording the thermal reradiation. Calculated PTR signals and signal‐to‐noise ratios are found to compare well with those observed.