Blood haemoglobin and serum ferritin levels were measured at the initial visit and 12 months following sterilization and IUD insertion. Ferritin levels were unaltered in Progestasert users after 12 months but haemoglobin values increased though not significantly. Ferritin levels fell in Multiload Cu 250 users and in sterilized women; haemoglobin levels were also observed to fall but significantly only in the latter group. Iron-deficiency anaemia was prevalent at initial contact and there appeared to be an increased risk subsequently in Multiload Cu 250 users and in those who were sterilized. Screening and monitoring for anaemia is indicated. From the viewpoint of iron status, the Progestasert is preferable to the Multiload Cu 250 but it suffers the major disadvantages of needing frequent replacement and of causing menstrual disturbances which might compromise its acceptability. Menstrual blood loss studies may help explain why anaemia develops after sterilization.