Autoimmune haemolytic anaemia (AIHA) in infancy is rare. We report a c
ase of AIHA in a male infant whose serum contained an antibody with ap
parent anti-Kp(b) specificity. Autoantibody with anti-Kp(b) specificit
y has been described in adults; to our knowledge, this is the first ca
se of this kind described in infancy with AIHA. Clinical course and re
sponse to red cell transfusion are described.