Oxidative stress is one of the main reasons of both menopause and diabetes. So, it plays crucial role in the pathogeneses of that condition and disease. Therefore, the objective of the present study was to investigate the effects of menopause and diabetes upon the hippocampus using a rat model. Adult female Sprague Dawley rats (n=24) were allocated randomly as follows; control (C group) ovariectomized (O group), diabetic (D group) and ovariectomy plus diabetic groups (DO group) (n=6; in each group), respectively. For evaluating the results, tissue biochemistry and stereological analysis were made. Biochemistry results (lipid peroxidase (LPO); catalase (CAT); superoxide dismutase (SOD); total glutatyon (GSH); and myeloperoxidase (MPO) values) in Group C-DO were determined as 12.27, 21.88, 23.08 and 29.90 nmol/gr tissue; 59.3, 70.06, 69.7 and 78.1 mmol/min/mg tissue; 174.2, 156.4, 159.7 and 154.6 mmol/min/mg tissue; 3.63, 3.61, 4.21 and 3.97 nmol/mg tissue; and 5.05, 5.68, 5.58 and 6.19 mu mol/min/mg tissue, respectively. Moreover, both menopause and diabetes led to change of lipid profiles. There were significant differences between the control and other groups (Group C and D-DO) (p<0.01) and among experimental groups (p<0.01) in terms of neuron number. When the volumes of the hippocampus were compared, there were no significant differences between the all groups (P>0.05). At this point, we suggested that diabetes could aggravate deleterious effects of ovariectomy.