Purpose: To investigate the effect of the aqueous extract of Achillea millefolium on recognition memory in mice.

Methods:  Male mice (35) were used. The aqueous extract of A. millefolium was prepared using a Soxhlet apparatus and injected intraperitoneally in a dose of 50, 250, 500 or 1000 mg/kg daily for 20 days. The control group was treated with saline 1 ml/mouse/day. Tactile learning was assessed using the novel object recognition test (NORT) in a dark room which entailed measurement of the distance travelled during trial and test phases.

Results: Treatment with different doses of A. millefolium did not affect activity levels (based on the distance travelled during trial and test phases). The total time and frequency of visits to the sample objects in trial and test phases were not statistically significant between control and A. millefolium treated groups (p >  0.05). A comparison of the discrimination ratio between the experimental groups revealed no difference. Administration of A. millefolium extract for 20 days did not decrease body weight or cause death in the treated animals.

Conclusion: The result of this study demonstrates that chronic treatment with different doses of the aqueous extract of A. millefolium did not impair recognition memory in mice.