Abstract: A storm water inlet filter system is disclosed which comprises at least two, but preferably three, distinct filter layers. The storm water inlet filter system uses a nested basket structure in which one filter basket fits within another. Preferably a piece of disposable filter media is placed within the internal basket. Polluted water flows first into the inner basket, and onto the disposable filter media. Overflowing water passes into the outermost basket which can remove debris. The storm water inlet filter system can be used with many existing drainage systems, and can be cleaned and the disposable filter media replaced without the use of specialized equipment or training.