In recent decades, many research groups have focused on the role of viral infections in the etiopathogenesis of systemic lupus erythematosus (SLE), the so-called "viral hypothesis". The main candidates are herpes viruses such as Epstein-Barr virus (EBV) and cytomegalovirus (CMV), which have a high seroprevalence in the general population. However, a viral causal agent of SLE has not yet been discovered, although many interesting clinical findings on the complex interactions between viruses and SLE have been made. This review analyzes 88 cases of acute viral infections in adult patients with SLE and identifies situations in which viral infections influenced the diagnosis, prognosis or treatment of SLE. We also propose clinical guidelines for the management of these infections in patients with SLE.