The present study was set to demonstrate the prevalence of toxoplasmosis infection and its effects on patients with systemic  lupus erythematosus (SLE) through determining their serum levels of anti-dsDNA and IL-18 antibodies. For this purpose, the sera from 132 SLE and/or toxoplasmosis patients and 30 healthy women, were collected. The study sample was divided into four groups of SLE, toxoplasmosis, SLE coinfected with toxoplasmosis, and healthy control. Anti-Toxoplasma IgG antibodies were examined for all the samples using ELISA kit. The results showed a high mean level of anti-Toxoplasma IgG among SLE patients coinfected with toxoplasmosis (104.8792±12.31585pg/ml) in comparison to that in toxoplasmosis patients (91.1705±12.57746pg/ml). However, the mean value of anti-dsDNA antibodies showed significant (P≤0.01) elevation  in SLE patients and SLE patients coinfected with toxoplasmosis (71.2134±9.22131pg/ml and  72.3699±9.67917 pg/ml, respectively), compared to those infected with toxoplasmosis only and healthy control. Furthermore, the IL-18 mean value in the sera of the studied patients showed significant (P≤0.01) elevation (418.4000±43.18072pg/ml) in SLE patients with toxoplasmosis in comparison to  SLE patients (354.4400±35.29257pg/ml). The present investigation suggests that the  levels of anti-Toxoplasma IgG antibodies seem to increase in patients with SLE.