The control of land mollusks, one of the most damaging agricultural pests in the world, depends on synthetic molluscicides. Thus, the creation of eco-friendly alternatives to traditional molluscicides is necessary. So, this study aimed to determine the molluscicidal activity of the monoterpene compounds, Thymol and Thyme essential oil against adult's Succinea putris (S. putris) and Eobania vermiculata (E. vermiculata) land snails. Contact technique gave better results than did poisonous bait technique. In comparison to E. vermiculata, the land snail S. putris showed greater sensitivity to all compounds tested. The results exhibited that Agrinate was the most effective one followed by Thymol (the active ingredient), and then Thyme essential oil which had the lowest affect against the adult of S. putris and E. vermiculata with LC50 (593.30, 1570.51 and 224.14 ppm) and (1577.48, 3344.91 and 873.59 ppm), respectively using contact technique. When thymol, thyme oil, and Agrinate, used as poisonous bait, they have LC50 values of (0.77, 2.29, and 0.31%) and (3.44, 6.31, and 1.36%) for S. putris and E. vermiculata, respectively. Also, Thymol prevents mold formation and has antifungal activity in poisonous bait. The results showed that using Thymol to control harmful land snails would be as effective as using synthetic molluscicides.