In this prospective study of 416 children in a computerised immunisation recall system, 78% attended voluntarily. A further 16% attended with prompting and of the remainder the majority are being followed up by the public health nurses. The system identifies individual children who have missed out on a specific immunisation and enables the omission to be corrected close to the most appropriate time. Sixty-seven children who were omitted were subsequently immunised in the sixth month period studied.