Cancer and other prevalent diseases such as heart disease, rheumatoid arthritis, stroke, and diabetic retinopathy are directly associated with either an increase or decrease in levels of angiogenesis in the body. High-frequency (HF) ultrasound (10-100 MHz) is particularly sensitive to small vascular structures that are close in size to the ultrasound wavelength (15-150 μm). The ability to rapidly determine the degree of vascularization in the development of small animals in vivo would provide a useful characterization tool for the study of a variety of diseases. The objective of this study was to determine if HF ultrasonic measurements could identify microscopic vessel formation that occurs during the development of zebra fish embryos within 1-3 days post-fertilization (dpf). Casper and P53 Nacre zebra fish embryos were provided by the Stewart Lab at the Huntsman Cancer Institute (Salt Lake City, Utah). The embryos were placed in 12-well cell culture plates, embedded in agarose and egg water, and immobilized with tricaine. Embryos were positioned on their lateral side and tested 1-2 dpf using 50-MHz pulse-echo measurements. The results show that the number of peaks in the ultrasonic spectra correlate with embryo development and may provide a quantitative assessment method for angiogenesis.