Installation of a rotary analyser to replace manual methods has resulted in reduction of staff and space requirements, results are available earlier and work capacity has increased. The equipment was a Union Carbide ‘Centrifichem’ without the optional computer attachment. The latter is considered desirable where large enzyme workloads are contemplated but unnecessary for most other estimations. Within two weeks the equipment was used routinely for the serum measurement of glucose, urea, creatinine, uric acid, protein, albumin, bilirubin and enzyme estimations (SAP, γGT, AsA.T, AIA.T, LDH, HBDH and CPK). Cholesterol, triglyceride, acid phosphatase and amylase methods are being assessed. Accuracy of results has been compared with those of methods previously used. A number of previously used methods were easily modified allowing us to prepare our own reagents. In other cases reagents and methods from various commercial suppliers have been compared. Some initial problems were experienced because of instability of commercial reagents. The capacity for rapid, multiple analyses allowed early establishment of our own normal ranges. This was especially advantageous when method modifications were made. Some groupings of tests were made for laboratory convenience, only abnormal unrequested results being reported. Rapid method changeover allows easy interspacing of urgent tests with the routine work. Service requirements in the initial period were higher than anticipated, probably due to the newness of the equipment. Servicing has been practical during slack periods and the equipment has been used daily without recourse to alternative methods.