The molluscicidal effect of the aqueous extract of Thymus vulgaris (thyme) on the land snail Eobanica vermiculate was tested. Snails showed morphological alterations, such as swollen of the snail body due to water retention, which led to slow motion of snails, protrude of tentacles and foot due to their enlargement. Abnormal bully-like structure appeared at the head region (a swollen part of the skin filled with aqueous material). Samples of the integument, bully-like structure, mantle edge, digestive gland and gonads were dissected out and prepared for histological examination under light microscope. Some morphological tissue abnormalities were recorded. The highest mortality rate (83.3%) was recorded at concentration 12.5%. The estimated LC₃₀,LC₅₀ and LC₉₀ were 5.832, 8.029 and 13.398 respectively. The plant extract used was chemically analyzed by high performance liquid chromatography (HPLC) to determine its active ingredients. The first five ingredients that have the highest concentrations were 2-Bromo dodecane, 3-methylindole, n-Tricosane, Octadecanedioic acid and Tetradecanedioic acid dimethyl ester.