Cytomegalovirus (CMV) infection is a common and typically benign disease in immunocompetent individuals. However, immunocompromised patients are at a greater risk of reactivation, leading to more severe outcomes. Patients with rheumatic diseases have a particularly high risk of opportunistic infections due to both the inherent immunosuppressive state conveyed by the disease itself and the use of potent immunosuppressant drugs, such as glucocorticoids, cyclophosphamide, and rituximab. Limited data are available regarding prophylactic or preemptive treatment of CMV infection in patients with rheumatic diseases. In this article the authors present two cases of rheumatic conditions complicated by CMV infection. The first case describes a patient with eosinophilic granulomatosis with polyangiitis, previously treated with glucocorticoids and cyclophosphamide, who developed CMV colitis with bowel perforation. The second case involves a woman with systemic lupus erythematosus who was diagnosed with CMV meningitis. Both cases reinforce the importance of establishing guidelines for surveillance and prophylaxis of CMV infection in these patients.