Diffuse infiltrative lymphocytosis syndrome (DILS) is characterised by a persistent CD8⁺ lymphocytosis and lymphocytic infiltration of various organs. The reported prevalence varies between 0.85–3%, and appears to be more common in Africans. Patients with DILS tend to have higher CD4⁺ cell counts and survive longer than those patients without DILS. Most patients present with bilateral parotid gland enlargement and features of the Sicca syndrome. Extraglandular involvement is common with the lungs being the most common site, followed by peripheral neuropathy and liver involvement. DILS is a benign presentation in most patients with few complications. Therapeutic trials are lacking although there are isolated reports of good response to antiretroviral and steroid therapy. With the high incidence of HIV in our population it is likely that DILS is under diagnosed probably due to our ignorance of this disease. Awareness of its various presentations may bring to light undiscovered patients with DILS.