Forced diuresis (FD) is a frequently used method for eliminating toxins. Its therapeutic effect has yet to be evaluated by a controlled clinical trial. In the absence of such a trial its usefulness can be judged only indirectly from urinary excretion rates. In former times the usual clinical laboratory procedures could not differentiate between the unchanged toxin and its metabolites. Using more selective methods, the discussions of the effect of FD in eliminating various drugs were renewed. The problem for the indication of FD is not only a missing knowledge about the kind and amount of the ingested drug, but also when knowing it, the missing evaluation of the effect of FD on its excretion. In such cases the pharmacokinetic behaviour of the drug can be helpful. If paying enough attention to the contraindications, to the principles of electrolyte and water balance, the complication rate is low. Many infusion regimes are proposed for this treatment, but only a standardized procedure can increase the safety and efficiency of this method. More complicated and more expensive methods should be used, when there is an intoxication with a substance of high mortality or when there is no effect of FD on eliminating the toxin.