Abstract: To evaluate the allelopathic effect of Papaver somniferum against the 3 varieties of Zea mays seeds cv. Azam, Pahari and Iqbal. Aqueous extracts were made by soaking the powder of dried leaves of Papaver somniferum. For the aqueous extract treatment, the extract was soaked in distilled water for 24 and 48 hours separately. For mulching treatment, the seeds were sowed in soil and sprinkled powder of leaves. For litter, the petri dishes were grounded with randomly cut pieces of filter paper wetted with extract. For hot water treatment the water was boiled for 5 minutes. The powder was then mixed in boil water. Azam got effected in 24h extract in aqueous extract treatment while Pahari in 48h treatment. In mulching all the three varieties got inhibited by extract. Azam showed resistance toward the inhibitory effect of extract in litter experiments. Iqbal was affected in hot water extract. It is concluded that the extracts obtained from Papaver somniferum showed inhibitory effects on all the three varieties except few exceptions in treatments.