Thrombocytopaenia is defined as a blood platelet count of less than 100,000/μL. Thrombocytopaenia can either be isolated or associated with the clinical picture of various disease entities. The paper presents three cases of children who developed thrombocytopaenia secondary to other diseases: a 3-month-old infant with thrombocytopaenia induced by cytomegalovirus infection; a 10-year-old girl with autoimmune lymphoproliferative syndrome and thrombocytopaenia observed at the time of diagnosis; and a girl aged nearly 2 years, later diagnosed with myelodysplastic syndrome based on bone marrow biopsy results. The topic discussed by the authors is extremely important in the daily work of general practitioners and paediatricians, as appropriate selection of patients with thrombocytopaenia who should be referred to specialists for an extended diagnostic work-up plays a crucial role in the therapeutic management.

thrombocytopaenia, cytomegaly, myelodysplastic syndrome, autoimmune lymphoproliferative syndrome