The purpose was to compare the bone samples histomorphometrically regarding trabecular bone properties in the patients with osteoarthritis (OA) and osteoporosis (OP). Femoral head specimens were obtained from 18 patients with OA and 17 patients with femoral neck fracture due to OP during hip arthroplasty. Histomorphometric analyses were performed by soft ware program (Carl Zeiss) to measure trabecular area (Tb.a, mm(3)), trabecular thickness (Tb.th, A mu m) and trabecular separation (Tb.s, A mu m). In the results, Tb.a and Tb.th values were significantly lower (p < 0.05), Tb.s was higher in the patients with OP (p < 0.05). Bone metabolism parameters were different between the groups (p < 0.05). All histomorphometric parameters were highly correlated with the BMDs (p < 0.01). This study showed inverse relation between OA and OP regarding trabecular bone properties, BMD and bone turnover metabolism markers. The strong relations between results suggest that either BMDs or bone turnover markers can be used for prescience of the fractures.