A method for remote sensing of cloud parameters by using infrared sounder data has been developed on the basis of the parametrized infrared transfer equation applicable to cloudy atmospheres. The method is utilized for the retrieval of cloud height, amount, and emissivity in the 11-μm region. Numerical analyses and retrieval experiments have been carried out by using synthetic sounder data for the theoretical study. The sensitivity of the numerical procedures to the measurement errors are also examined. The retrieved results are physically discussed and numerically compared with the model atmospheres. Comparisons reveal that the recovered cloud parameters agree reasonably well with the preassumed values. However, for cases when relatively thin clouds and/or small cloud fractional cover within a field of view are present the recovered cloud parameters show considerable fluctuations. Experiments on the proposed algorithm are carried out by utilizing High Resolution Infrared Sounder (HIRS/2) data of NOAA 6 and TIROS-N. Results of experiments are difficult to verify quantitatively, but the retrieved cloud amounts show reasonably good comparisons with the surface reports and GOES satellite images.