The purpose of this document is to present a concise survey of the state of the art in advanced ultrasonic testing systems, techniques, and system components. Information presented is intended to give a practical overview of the types of ultrasonic nondestructive inspection apparatus presently in use and of relatively new techniques which are being applied to improve the capabilities of such systems. Computer retrieval facilities of the Nondestructive Testing Information Center (NTIAC) were used to search the open literature in ultrasonics and related subjects from 1968 through 1975. Technical uournals, conference proceedings, research reports, Department of Defense technical reports, and trade journals were included in the body of literature surveyed. This state-of-the-art survey includes discussions on (1) automated ultrasonic inspection systems for a variety of applications, (2) signal processing techniques as applied to ultrasonic inspection systems for a variety of applications, (2) signal processing techniques as applied to ultrasonic inspection, (3) ultrasonic imaging systems, including direct and holographic types, (4) methods of inferreing material properties from ultrasonic measurement, (5) special ultrasonic techniques (i.e., the Delta technique and stress enhancement of fatigue crack detection), and (6) ultrasonic inspection system components including transducers, scanning devices, and pulsers. Because of the magnitude of the subject covered by this survey, discussions of individual items are necessarily briefy; frequent references are made to the literature from which the reader may obtain detailed information.