Chandrasekhar's work in radiative transfer theory began in 1944 and cu
lminated with the publication of his influential treatise Radiative Tr
ansfer in 1950. In this review his major contributions to radiative tr
ansfer will be recounted and evaluated. These include his development
of the discrete ordinates method, the invariance principles, and his f
ormulation and solution of the transfer equation for polarized light.