A system for separating particulate solids and condensable vapor materials from a hot feed gas stream such as a fuel gas containing such materials, so as to provide a clean gas product stream. The system includes a cyclone-type separator in which coarser particulate solids are removed downwardly, and an overhead gas stream containing a reduced concentration of finer particles is passed through a cooling step such as a heat exchanger for solidification and removal of condensable materials, and then passed to a filter vessel. In the filter vessel, the cooled gas and solidified particles pass through a filtering surface for further removal of the finer particles and solidified materials, after which the cleaned product gas is removed through an upper outlet connection. The coarse particles from the cyclone separator are passed downwardly through a conduit to the filter vessel lower portion where they are mixed with the finer particles removed by the filter surface, after which both fine and coarse size particles are withdrawn from the lower portion of the filtering vessel. The invention also provides a method for separating particulate solids and condensable species from a feed gas stream such as a fuel gas at 500.degree.-1800.degree. F. temperature and 50-500 psig pressure, and containing solid particle size distributions with top sizes of 50-4,000 microns in solids concentrations of 0.5-80 wt. percent.