A total of sixty women with a history of abortion and twenty-four healthy-looking controls were included in this study. Forty-four women were found to have Toxoplasma infection, fourteen women with anl\-Toxoplastna IgM antibody (acute infection), eighteen with anti- Toxoplasma IgG antibody (past or chronic infection), and twelve with both IgG and IgM antibodies (recurrent infection). Venous blood was collected from the patients and controls and divided into heparinized blood for immunostaining and cytogenetic analysis, and serum for anti-Toxoplasma antibody detection in addition to the measurement of the ADA, sodium, potassium and copper. The results indicated a high incidence of the infection (73.3%) among women with abortion in Baghdad and this may be due to the multiple pathways of parasite transmission. The use of ELISA for the detection of ani-Toxoplasma antibody was a sensitive but not highly specific method, for the sensitivity was (91.6%) and specificity was (55.5%). Toxoplasma infection was found to be characterized by a detectable cell-mediated immunity and this fact was confirmed by the immunostaining of lymphocytes using different activated antigens (CD markers). In this study CD3, CD4, CD8, and CD71 were used and the results showed a significant elevation of these markers in women with toxoplasmosis when compared to the healthy controls. Cytogenetic analysis was used in this study as a marker to reflect the genotoxic effect of ToxopJasma parasite on the lymphocytes. The M.I. and R.I. means in this study were found to be significantly lower in the patients than in healthy controls and this may be because of the effect of the Toxoplasma infection on the lymphocytes. While S.C.E. mean showed a significant increase in the patients when compared to the healthy controls. This may indicate a chromosomal damage that has occurred which may be due :o multiple factors including drug administration and sensitization of \rnphocytes or the change in the lymphocyte population. ADA level was used in this study as a further marker to estimate the immune status of infected women and the results show;ed a significant increase of ADA level in the patients that have anti-Toxop/aswa IgM when compared to the other patients and controls. This may indicate the elevated CMI in this phase compared to other parasitic infection. K-/Na+ ratio was measured in this study and the results showed there was a significant increase in this ratio in the patients when compared to the controls. Cu was used as an indicator to the immune response. Xo significant difference was found between the patients and the healthy controls. This result does not necessary indicate that there was no immune activation but may be due to other factors like other illnesses and imbalanced diet.