Abstract: The anticonvulsant activity of diazepam has been investigated in mice using an electrical low voltage square wave technique. Diazepam was administered intravenously using two injection formulations, valium® inj. (Roche) and diazepam emulsion. In the latter formulation the lipophilic drug was dissolved in soya bean oil which was then emulsified to an o/w emulsion. A great difference was found in acute intravenous toxicity (LD50) between the two diazepam formulations. The higher toxicity of valium® inj. could probably be due to the solvents used in this formulation. The anticonvulsant activity was about equal for the two preparations. Thus, no difference was found in duration of anticonvulsant activity at the two dose levels and the slopes of the log. dose‐response curves did not differ.