This study was done to assess the anxiolytic, antiamnesic and antioxidant potential of Rosmarinus officinalis essential oil, in three concentrations 25, 150 and 300 ml / L (Teipel et al., 2018) Methodology: Anxious behavior and memory performance were assessed by NTT (new tank diving test) and Y and T mazes, and scopolamine (100 μM) was administered by immersion 30 minutes before behavioral testing to induce anxiety and a mild dementia.(Zanandrea et al., 2018) Results: Our data has shown that essential oil of rosmarin has diminished anxious behavior and amnesia induced by the use of scopolamine in parallel with the decrease in oxidative stress in the zebra fish brain. Discutions: The essential oil of rosmarin is known for its antiinflammatory effects due to its compounds - α-pinene, camphor, eucalyptol - the chemical composition being identified by GC-MS (Borges et al., 2018). At the same time, literature mention the anti - amnesic and anti - acetylcholinesterase effects of rosemary essential oil in a scopolamine - induced Wistar rat animal model (Ozarowski et al., 2013). Conclusions: The results obtained from the behavior of zebrafish behavior in the three behavioral tests show a significant difference between the activity of scopolamine-treated animals and those exposed to rosmarin oil, especially in the concentration of 25 μl / L. In conclusion, the essential oil studied could be considered a good candidate for improving memory by inhibiting acetylcholinesterase and reducing oxidative stress in the brain.