For severe lithium intoxication haemodialysis is recommended to lower serum lithium levels rapidly. Frequently, serum lithium levels rebound after dialysis and repeated dialysis is needed. This is the first report of an adult patient with severe lithium intoxication who underwent haemodialysis (HD) followed by continuous veno-venous haemodiafiltration (CVVHDF). Mean lithium clearances with HD and CVVHDF were 173 and 61 ml/min, respectively. Serum lithium levels were rapidly lowered and did not rebound. Two compartment simulations illustrate that HD followed by CVVHDF is the most effective strategy for removing lithium from the intracellular compartment.