Antifertility effect of Andrographis Paniculata (AP) was observed in mice under different experimental conditions. When sun-dried powder of AP was mixed with animal's food (Rats Pelletts) in a dose of 2G per Kg. B.W. per day and was allowed to consume by the female mice daily for a period of six weeks, none of the animal (100%) were pregnant when mated with the male of proven fertility who did not receive the drug. On the other hand, the majority of the control female mice (95.2%) who did not receive the drug were pregnant when mated with the similar type of male as in the experimental group, and they continued to give birth to litters of usual size and number (average 5-6) for subsequent six matings.