Since 1982, "automated intelligence microscopy" (AIM) has been refined and adapted to perform the portion of the urinalysis profile traditionally done by a microscope. AIM and analytical subsystems measuring relative density and performing dipstick chemistry compose the main elements of "The Yellow IRIS" urinalysis workstation, an attended system for automation and standardization of routine urinalysis. Performance data gathered at three laboratory test sites show AIM to be analytically consistent over the required range of particulate enumeration, and show that it detects 20% more abnormalities than by conventional microscopy, and with greater precision (CVs 5 to 20%). Complete urinalysis, including the microscopic examination, requires little more than 1 min for normal specimens, 3 min for most abnormal specimens. Actual throughput rate varies with the particulate composition of specimens; typically, it averages greater than 30 specimens per hour, a 300% improvement in urinalysis productivity by CAP standards and an almost 500% improvement when typical emergency-use demands are taken into account.