Laboratory and field experiments have been conducted to evaluate the molluscicidal activity of certain biocides compared with neomyl (methomyl, the recommended compound) against the two land snails Monacha cartusiana and Succinea oblonga in Plant Protection Research Institute Sakha branch, Kafr El-Sheikh Governorate during 2011. In the present study agreen, biogard, protecto, delfin and neomyl tested at concentration of 0.5, 1 and 1.5 % as leaf dipping technique against the two investigated land snails. LC₅₀ and LC₉₀ values were "1.73, 1.12, 1.57, 1.86 and 0.44 %", "9.77, 6.58, 10.99, 5.33 and 1.46%" and "11.81, 0.17, 8.55, 0.20 and 0.05%", "51.17, 0.89, 22.97, 0.59 and 0.37%" for M. cartusiana and S. oblonga, respectively. On the other hand, LC₅₀ and LC₉₀ values as poison bait were "2.98, 2.14, 3.55, 1.98 and 0.67%", "37.13, 17.66, 39.40, 16.32 and 1.41%" and "1.64, 1.10, 2.03, 1.03 and 0.11%", "29.12, 15.32, 32.21, 17.68 and 0.51%" for the two land snails, respectively. The laboratory observation indicated that S. oblonga was more sensitive to the tested biological insecticides and pesticide neomyl than M. cartusiana. Field results showed that the tested biocides reduced population density of the two land snails with comparable low values of 50 to 55% after 28 days residue effect.  On the other hand, this study revealed that neomyl was most effective (91% reduction) to population density.