The present invention disclosed a method of conducting acute toxicological studies of pharmaceutical compounds by using chick embryo chorioallantoic membrane, CAM model and calculating the ideal median % of mortality, ideal LD50 values of the chick embryo. The chick embryo ideal LD50 values determined according to the present invention show correlation with the LD50 values from the conventional mice and rats models. This showed that the chick embryo is a suitable alternative model for acute drug toxicity screening before embarking on full toxicological investigations in rodents during development of pharmaceutical compounds.