The present invention is concerned with a method and apparatus for recycling drilling fluids used in the drilling of wells. The apparatus comprises a tank with a plurality of compartments. Used drilling fluid containing well cuttings or "solids" is pumped into a receiving compartment of the tank and directed towards a flow-reversing barrier. Reversal of the flow causes heavier solids to settle to the bottom of the tank. As fluid fills the receiving compartment, it flows downstream into an adjacent compartment by passing through a flow-restricting baffle that causes more solids to settle to the bottom of the tank. As fluid overflows from compartment to compartment in the tank, it passes through successive flow-restricting baffles causing further solids to settle to the bottom of the tank. When the fluid reaches the collecting compartment of the tank, it is removed to be used again in drilling operations. A conveyor extending along the bottom of the tank is used to move the settled solids to the collecting compartment, from which they are removed and pumped through a centrifuge to recover residual fluids.