Estimation of regional soil moisture is of importance to the hydrological modelling community for validating the accuracy of model predictions and to the climate community for use in regional and global climate models. Soil moisture estimation is done in two ways, viz., estimation using models and estimation using satellite data. Both these methods have to be corroborated using in situ field data. The present paper examines the feasibility of using observations of brightness temperature from the Special Sensor Microwave Imager (SSM/I) for small scale/catchment scale studies. The simulations of the 19 and 37 GHz brightness temperatures are carried out for a period of 13 days between 6 and 21 August 1987. The comparisons between the simulated and the observed brightness temperatures are good and the errors can be explained based on the atmospheric and surface conditions. Sensitivity analysis of the brightness temperatures to leaf area index, soil moisture and soil temperatures shows interesting characteristics. The errors in the simulated brightness temperatures can be explained by variability in the input parameters. This study shows that such an approach holds promise for local and regional studies of the land surface.