Ciliary aplasia is a rare congenital disease that alters the normal function of the mucociliary apparatus in several organs. Patients generally present with severe recurrent and chronic infections of the airways. A high suspect of this disorder is mandatory to perform correct diagnosis and provide prompt treatment. The authors describe the history of two siblings affected by primary ciliary aplasia that was associated with hydrocephalus in one case. A careful description of diagnostic procedures and treatment of this extremely rare disorder is also presented.