The paper presents a case of congenital asplenia diagnosed occasionally in a child who previously presented with a pneumococcal sepsis. The case offers the opportunity to discuss about the elevated risk of severe invasive infections in patients with congenital asplenia and the importance of early diagnosis so to prevent infections by starting an antibiotic prophylaxis, adequate vaccinations and prompt antibiotic therapy with immediate medical consult in case of fever. First degree relatives should be concerned about the high frequency of autosomal dominant transmission of this condition and should be submitted to early follow-up.