Good's syndrome is the association of thymoma with immunodeficiency, characterized by hypogammaglobulinaemia, depleted B-cells, diminished T-cells and inversion of the CD4/CD8 ratio. The initial clinical presentation is either with a mass lesion-thymoma that is usually benign, or with recurrent infections due to immunodeficiency. Thymectomy usually favourably affects associated conditions, such as pure red cell aplasia, but does not improve hypogammaglobulinaemia, thus the patient remains dependent on intravenous immune globulin and prone to infections. Infections usually affect the respiratory and/or the gastrointestinal tract. Common respiratory, opportunistic, and eventually life-threatening infections may occur. Moreover, patients with Good's syndrome may present other haematological conditions. We report 3 cases with long follow-up, sharing some common manifestations of the syndrome, but also showing unique features. The principal features of this rare syndrome are further discussed.