It is known that silver nanoparticles (Ag NPs) and AgNO₃ have harmful effects on the surrounding organisms, which may cause damage to these organisms. Therefore, the aim of this study is to detect damage caused by Ag NPs and silver nitrate to land slugs (Lehmannia nyctelia). In this study, the slugs were exposed to various concentrations of Ag NPs and AgNO₃ for 15 days. The biochemical, antioxidant, lipid peroxidation (LPO), DNA fragmentation, and histopathological endpoints were assessed after 15 days of exposure to different concentrations of Ag NPs (0.04, 0.08, 0.4, and 0.8 g/L) and silver nitrate (0.04, 0.08, 0.4, and 0.8 g/L). The results show a significant decrease in total protein, total carbohydrate, superoxide dismutase, and GST and a significant increase in total lipid, LPO, and DNA fragmentation after exposure to Ag NPs and AgNO₃ for 15 days compared with the control group. Histopathiological alterations were observed in the digestive glands which were indicated by histochemical staining. We concluded that exposure to AgNO₃ and Ag NPs caused oxidative stress, genetic damage and alterations in the profile of muscle proteins and histological structure in L. nyctelia.