Different soil moisture estimation models have been developed based on using optical, radar, or a combination of optical and radar data. However, it is not clear which of these models is more suitable to estimate soil moisture in vegetated areas. Soil moisture is estimated in sparse vegetated areas using both optical and synthetic aperture radar (SAR) images. Also a hybrid model that is based on a combination of SAR and optical derived indices is used to decrease the effects of vegetation cover on SAR backscatter coefficients. The results show that the SAR model is more accurate than the optical model. However, after using the hybrid model and removing vegetation cover effects from radar backscattering coefficient, the accuracies improve. This shows that the hybrid model is the most accurate model and can be used as a suitable model to estimate soil moisture.