A number of biochemical methods are available for measuring fat accumulation in cell culture. The authors report a simple image-based method for measuring fat accumulation in adipocytes using a combination of high-throughput brightfield microscopy and image analysis, which was validated biochemically using Oil-Red-O. The quickest and most accurate method of analysis was one based on thresholding brightfield images and determining the area of fat droplets per image. Thus, the authors have developed a simple high-throughput, label-free method for measuring fat accumulation that is applicable to any cell or tissue type where fat droplets are visible under light microscopy.