The differential diagnosis of mononucleosis infectiosa (Ml)-like illness can be challenging since several infectious causes have been identified to date. The most common associated pathogen is Epstein-Barr virus, followed by cytomegalovirus, human immunodeficiency virus type 1 and human herpesvirus-6. Ml-like illness is rather rarely caused by Toxoplasma gondii, a parasite that is transmitted through consumption of undercooked food or contact with faeces from infected cats. In this case report, we discuss a B-cell chronic lymphocytic leukaemia patient with a Ml-like illness caused by toxoplasmosis.

(BELG J HEMATOL 2019;10(3):122–6)