Abstract: An inverse analysis for simultaneous estimation of the radiation phase function, single scattering albedo and optical thichness in natural waters, from the knowledge of the exit radiance measurements, is presented. A forward and an inverse models are utilized in ou analysis. The forward model uses an an analytical discrete-ordinates method for solving the radiative transfer equation and the inverse model contains an algorithm for least-squares estimation that is iteratively solved for retrieving the desired optical properties. The experimental data are simulated with synthetic data corrupted with noise. The results show that the optical properties, with exception of the optical thichness, can be recovered with high accuracy, even for data up to 10% noisy.