Exposure to pollutants and nanoparticles has been associated with abnormal, impulsive, and risk-taking behaviors, as well as an increased risk of psychiatric disorders. Recent research suggested that a diet high in omega-3 fatty acids and plant-based meals may have a protective effect against these negative impacts. This study aimed to evaluate the potential protective effect of Thymus vulgaris (T. vulgaris) against aberrant behaviors caused by prenatal exposure to titanium dioxide nanoparticles (TiO2 NPs). Bulb-c mice were used in this study. Mice were exposed subcutaneously to 0.1 µg TiO2 NPs suspended in 0.1 ml distilled water at gestational day 2-20 with or without treated orally with 2.5 µg Ethanolic extract of T. vulgaris dissolved in 0.5 ml distilled water. The newborns were reared with their mothers until adulthood. At postnatal day 50, male mice were separated from their mothers then were used in the behavioral tests. The elevated plus maze (EPM), open field test, novel recognition test, actophotometer test, and tail suspension test (TST) were used to evaluate the behavioral changes caused by nanoparticle exposure. Gas chromatography-mass spectrometry (GC-MS) analysis revealed 36 different components in the T. vulgaris, including Thymol (9%), Quercetin (3.5%), and Apigenin (4.3%). The data obtained from the behavioral tests showed that mice exposed to TiO2 NPs demonstrated less anxiety, more impulsive-like behavior, depression-like behavior, more curiosity, and hyperactivity than control mice. However, mice treated with T. vulgaris significantly reversed anxiolytic, reduced impulsive-like behavior, reduced depression-like behavior, and less curiosity. T. vulgaris failed to adverse the effect of TiO2 NPs in locomotor activity. The results of this study suggested that T. vulgaris may have a protective effect against the adverse effects of prenatal exposure to TiO2 NPs in mice behavior except for the locomotor activity. The high levels of antioxidants, such as phenolic compounds and flavonoids, in Thymus vulgaris, were believed to be responsible for its protective effect. This finding highlights the potential of using plant-based foods as a protective measure against the harmful effects of pollutants and nanoparticles on brain function and behavior.