Estimation of the different types of the infections in SLE patients over a period of one year, find out the outcome of their infections, and their relationship to different aspects of the disease and to the drugs used in the treatment of the disease. Forty Egyptian SLE patients subjected to full history taking, complete physical examination, detection of infection’s clinical feature, and laboratory investigations (ESR, CRP, Blood picture, Liver and kidney functions, C3, C4, DNA titre, ANA, Urine analysis, Albumin in 24 hours urine, HCV-antibody and HBsAg) for initial visit, and (ESR, CRP, Blood picture, Liver and kidney functions, C3, C4, Urine analysis, Albumin in 24 hours urine) for 6 visits in one year. All the patients were surveyed for the detection of IgG and IgM of common viral and parasitic infections including the CMV, HSV, EBV, Toxoplasma, Rubella, HCV, HBV, and Bilharziasis, with any other investigation needed. One patient out of 40 patients (2.5%) was diagnosed as oral moniliasis and five patients out of 40 patients (12.5%) were diagnosed as herpes zoster infection, with no other clinical symptoms or signs of any other infection estimated. All patients (100%) possessed (IgG) antibodies against CMV, EBV and HSV; 37 patients (92.5%) possessed IgG antibodies against rubella virus; 19 patients (47.5%) possessed IgG antibodies against toxoplasma; 17 patients (42.5%) possessed IgM antibodies against CMV; 25 patients (62.5%) possessed IgM antibodies against HSV; and 4 patients (10%) possessed IgM antibodies against EBV, no patients (0%) have been found to be HBsAg positive, while 7 patients (17.5%) possessed IgG antibodies against HCV which are confirmed by positive PCR test. Also, there was no clinical manifestation for suspension of any parasitic infection, and none of the patients give positive results against antibilharzial test. There was no significant statistical difference on comparisons of the patients possessing positive and negative IgM antibodies detected for the CMV, EBV, and HSV regarding the different aspect of the SLE, except for the comparison of the TLC (P value < 0.05), ESR (P valve < 0.05) between patients possessing positive and negative IgM antibodies detected for HSV, and there was no significant statistical difference also on comparisons of the patients possessing positive and negative IgG antibodies detected for the Rubella virus, toxoplasma, and HCV regarding the different aspect of the SLE. As regards the possible effects of medications on the development of infections among patients, the results revealed no significant statistical difference between the results, except for the comparison of the cyclophosphamide pulses between the patients possessing +ve IgM antibodies against HSV and those that possessing - ve IgM antibodies which revealed highly significant statistical difference. On conclusion, we couldn’t diagnose any viral infection without presence of the clinical features, and confirmation by PCR test. We diagnosed 5 cases of HZ, and one case of oral candidiasis during one year. We also detected the percentage of the IgG and IgM antibodies of common virus infection [most common were IgM antibodies against HSV (62.5 %), and IgM antibodies against CMV (42.5 %)].