The efficacy of three known pesticides (methomyl 20% SL, methiocarb 2% GR and metaldehyde 5% GR) was evaluated as poison baits against adults of Monacha cartusiana under laboratory and filed conditions. The effect of time elapsed between preparation of poison baits and their offering to snails on the efficacy of these baits was also studied. Under laboratory conditions, results revealed that metaldehyde baits was the most effective while baits of methomyl were the lowest one and the poison baits of methiocarb occupied an intermediate position. Regarding the effect of time passing between preparation of baits and their use against snails, it was found that mortality percentages were decreased as the time passed.  Results under filed conditions cleared that methomyl and metaldehyde were more degraded rapidly by time passing while methiocarb awas more stable.