Using remote data entry, clinic staff enter patient data into a personal computer at the clinic and the data are promptly transmitted to a mainframe at the coordinating center. The author contrasts this new technology with conventional data entry, whereby case report forms are mailed to the coordinating center, where the data processing staff enters data directly to the mainframe. Remote data entry is found to be preferable to conventional when the remote software offers the possibility of driving clinic processes rather than merely transmitting outcome data to a mainframe. Some preliminary cost-benefit results are also presented.