This research aimed to develop prediction models for accurate estimation of performance and body measurements of beef cattle grown in feedlot beef system by using Digital Image Analysis (DIA). For this purpose, 40 animals were used in total and composed of 20 animals of the Brown Swiss breed and 20 animals of the Holstein breed with the age of about 4-5 months at the beginning of the experiment. Animals were fed the same dietary rations throughout the experimental period of 12 months. When the animals reached 500-550 kg bodyweights (BW), they were slaughtered. The digital images of each live animal were taken and the same parameters (digital wither height (DJWH), digital body length (DJBL), digital body depth (DJBD), digital hip width (DJHW), digital hip height (DJHH) and digital pin bone length (DJPL) were also determined from the images, using the data with 1069 observations for each traits. Then, prediction models were developed by DIA.