Nanotechnology has come a long way in our lives. However, it maintains some negative effects on the environment. This study aims to use the land snailHelix aspersaas a bioindicator. Titanium dioxide nanoparticles (TiO2NPs) had been used at 70 and 140 µg/L for two weeks by the spraying method. The oxidative biomarkers, condition index (CI), DNA damage, hemocyte count, and phagocytic activity were estimated. The toxicity of TiO2NPs was determined (LC50= 544 µg/L). The exposure to TiO2NPs caused a significant reduction of the activities of superoxide dismutase (SOD) and catalase (CAT) in the digestive gland ofHelix aspersa(the activity of CAT was 3.4 ± 0.1 (P= 0.001), SOD was 11 ± 1 (P= 0.0002) at concentration 140 µg/L after two weeks). The activity of glutathione peroxidase (GPX) was (1.13 ± 0.01 µ/mg protein at 140 µg/L compared with controls (5.47 ± 0.01 µ/mg protein). The treatment caused DNA damage in the hemocytes (tail DNA % = 8.66 ± 0.02 and tail moment = 52.99 ± 0 at140 µg/L (P= 0.002)). In the digestive gland, both tail DNA % and tail moment increased (tail moment = 78.38 ± 0.08 compared with control = 2.29 ± 0.09 (P= 0.0001)). The total count of hemocytes significantly decreased after two weeks (the average number was 71 ± 1.5 compared with controls 79 ± 1.1 at 140 µg/L). Furthermore, TiO2NPs caused histological alterations in the digestive gland ofHelix aspersa. It can be concluded that theHelix aspersacan be used as environmental pollution bioindicator. A comprehensive evaluation of toxic effects induced by TiO2NPs in vivo assays must be investigated.