Identification of complicated appendicitis (CA) is critical to the management of appendicitis. However, previous studies have not investigated indicators of CA among patients with HIV or whether it is safe to use conservative treatment for appendicitis in these patients. Among 322 patients with appendicitis, we identified 14 who had HIV. Six of them were operated and 8 were treated with antibiotics; CA was diagnosed in 4. Patients with HIV and CA had a significantly lower CD4+ T-cell count than those with uncomplicated appendicitis. A white blood cell count lower than 7.4 × 109/L was observed exclusively in patients with CA. No patient with HIV whose appendicitis was treated conservatively died or experienced a recurrence. We discuss our findings, which suggest the possibility of conservative treatment of appendicitis in patients with HIV and identification of CA by low CD4+ T-cell count.