Zinc phosphide, a commonly used rat poison in Kenya was mixed with maize flour in a concentration of 0.15% w/w and fed to a group of 60 experimental mice for 3 hours. The mice were then randomly divided into 5 equal groups A, B, C, D and E. To groups A, B, C and D was administered activated charcoal (3% w/v), sodium bicarbonate (10% w/v), hydrogen peroxide(0.5% v/v) and potassium permanganate (1:5000) respectively. Group E was given 1 ml distilled water and used as control. All five groups were observed for symptoms of toxicity, often culminating in death. The observations were continued over a period of 36 hours. Results of the experiment showed that all for test substances minimized the lethal effect of zinc phosphide. Although no attempt was made to quantify the antidotal effect of the 4 substances, activated charcoal appeared to have a higher effect than the others, while potassium permanganate had a low rating.