Fiber optic technology has made a very rapid transition from the research and development stage into practical operating systems. This transition has evolved in a natural progression towards more complex and demanding technology. This progression has resulted in wide application of multimooe systems and increasing deployment of single mode technology. Finally, optical-guided-wave and integrated-optical devices are beginning to emerge into the commercial arena. In all these cases, reliability is a prime concern that must be addressed. Considerable progress has been made in this area with regard to conventional multimove and single mode components and systems. However, the reliability aspects of optical-guided-wave ((JGW) devices are just beginning to be studied. This paper will discuss reliability considerations in TiLiNb03 puided-wave devices. These considerations will include material factors, device structures and designs, and packaging and connection of optical fiber pigtails. In the first category, processing/material factors will be reviewed and photorefractive, pyroelectric, and humidity effects will be discussed. The impact of packaging and pigtailing upon reliability will be covered. Test data on pigtailed 1i:LiNb03packaged devices under theermal, shock, and vibration exposure will be presented and discussed.