Biochemical and hematological changes may show insight into metabolic events of menstruation. However, there appears to be paucity of information with regards to protein pattern in menstruation among the Igbo community especially since these factors are known indices in monitoring health and disease. Therefore, this work was designed to explore the changes in some biochemical and hematological indices during menstruation in young women of Igbo ethnic group in Nigeria. A cross sectional study involving 140 young Igbo women aged between 18 and 36 y was recruited in Enugu Nigeria and willingly participated in the study on the second day after the onset of menstruation and one week after. Blood samples were collected from all subjects for the measurement of both biochemical (total protein, albumin, globulin, phosphate, calcium) and hematological indices (hematocrit, hemoglobin and reticulocyte). Standard routine methods were employed for all determinations. The results showed significant difference (P<0.001) in serum globulin concentration during menstruation (2.6 ± 0.52 g/dl) and one week after menstruation (3.6 ± 0.80 g/dl). Other measured parameters: Total protein, albumin, calcium, phospholipids, hematocrit, hemoglobin, reticulocyte showed no significant difference (P>0.001) when compared. The same pattern of result was obtained when were compared on the basis of age, difference in menstrual cycle and number of bleeding days. The results suggest that menstruation affects globulin concentration in this ethnic group of Nigerians and this may have direct link and help in the explanation of some aspects of osteoporosis in women.