It is reported that the usage of high-dose intravenous immunoglobulin (HD-IVIG) in systemic autoimmune iseases is associated with various adverse events in a wide range of severity. We aimed to investigate the frequency and profile of adverse events in a group of patients with diffuse connective tissue diseases and Wegener's granulomatosis (WG) who were administrated HD-IVIG for different indications. We recorded the data of 38 patients (25 females and 13 males) aged 38 +/- 15 (12-75) years who were followed up with the diagnosis of systemic autoimmune diseases between 1994 and 2006 according to a predefined protocol. Patients with active disease were treated with HD-IVIG and standard immunosuppressives concomitantly. We evaluated the occurrence of allergy, acute renal failure, thromboembolic events, neutropenia, hemolytic anemia, aseptic meningitis, and vasculitis during infusion therapy of HD-IVIG and in the following 3 weeks. We commenced a total of 130 infusions of HD-IVIG. Patients were administrated 1-12 (3.4 +/- 2.6) infusions of HD-IVIG as needed. Indications for HD-IVIG were unresponsiveness or partial response to standard treatment, severe infections along with disease activity, and severe thrombocytopenia in the preoperative period in 97, 23, and 5% of patients, respectively. Minor adverse events were seen in two patients during HD-IVIG infusions. One patient with WG developed rapidly progressive renal failure during severe disease flare between HD-IVIG infusions. Another patient with WG developed recurrence of deep-vein thrombosis during severe disease flare 3 months after HD-IVIG. Both events were attributed to severe disease activity. Adverse events like allergy, acute renal failure, thromboembolic events, hematological problems, aseptic meningitis, and vasculitis are reported in different frequencies (1-81%) in patients who were administered HD-IVIG for systemic autoimmune diseases. HD-IVIG is considered a safe treatment in selected patients assuring adequate infusion precautions.