A cell analyzer that combines the characteristics of image cytometry and flow cytometry is being designed and constructed at the University of Sydney. This paper describes the image acquisition and processing components and some preliminary applications. Cells stained by a fluorescent dye and suspended in a liquid medium are conveyed by a hydraulic system to a flow channel assembly, where they are detected and illuminated by a laser beam. A two-dimensional charge-coupled device is used to acquire the cell images. Image processing and classification is to be carried out by a special-purpose computer comprising an array of four conventional microprocessors and a highly parallel processor consisting of an array of 32 X 32 processing elements. The analyzer will be capable of using morphologic, immunologic and biochemical information to classify and sort up to 500 cells per second. Because of its unique characteristics, the instrument will be of particular use in tumor heterogeneity studies.