Much research has been conducted to investigate the effects of environmental and nutritional treatments on ovarian development in poultry. However, to investigate the ovary, the hen must be killed, and thus, lifelong egg production can only be inferred. To date, the ability to noninvasively determine ovarian status has not been available. Improvements in ultrasound technology now make it possible to observe ovarian condition in vivo, thereby allowing for repeated sampling of the same bird over an entire egg production cycle. In the current study, large yellow follicles (LYF; diameter greater than 10 mm) were characterized in broiler breeder hens using Aloka ultrasound diagnostic equipment. Ultrasound images were used to determine the number and diameter of the LYF as well as the presence of an egg in the oviduct. Immediately following ultrasonography, hens were killed and dissected to determine the number and diameter of LYF. From the ultrasound images, the number of LYF +/- 1 was predicted with 96.3% accuracy in Experiment 1 and 93.3% accuracy in Experiment 2. Diameter measurements were used to classify follicles hierarchically. Of the birds determined via dissection to have multiple hierarchies, 77.8% were identified with ultrasound. All regressing or regressed ovaries were correctly identified with ultrasound.