This paper reports attempts to make results of clinical chemistry tests carried out on children more meaningful. Results of tests performed on the initial blood sample obtained from patients over an 18-mth period were transferred to punch cards and processed on a Burroughs 500 Computer using programmes written by one of us (F.L.M.). Patients were classified according to age, sex and location, and specimens according to nature of blood collection and time of day. The initial print-out of each test showed the number and percentage of patients with each result and the cumulative percentage over each range observed. The study has provided previously unknown information about results obtained by the laboratory and has assisted in deriving reference ranges for various groups within the hospital population. By liaison with the Medical Records Department, diagnoses of patients with extreme values and the pattern of findings in particular disorders have been obtained. This paper reports attempts to make results of clinical chemistry tests carried out on children more meaningful. Results of tests performed on the initial blood sample obtained from patients over an 18-mth period were transferred to punch cards and processed on a Burroughs 500 Computer using programmes written by one of us (F.L.M.). Patients were classified according to age, sex and location, and specimens according to nature of blood collection and time of day. The initial print-out of each test showed the number and percentage of patients with each result and the cumulative percentage over each range observed. The study has provided previously unknown information about results obtained by the laboratory and has assisted in deriving reference ranges for various groups within the hospital population. By liaison with the Medical Records Department, diagnoses of patients with extreme values and the pattern of findings in particular disorders have been obtained.