Agricultural crops improved through genetic engineering raise expectations of enhanced agronomic, nutritional, and marketing qualities, as well as numerous other benefits. These samecrops also raise concerns about their potential long-term effects on human health and the environment. Such concerns have prompted developed and developing countries alike toimplement guidelines for the safe use and handling of genetically modified organisms (GMOs) in the environment. Appropriate oversight of GMO releases in the environment is achieved through the establishment of a biosafety system in which guidelines are the most visible part. Equally important in a biosafety system, however, are three other elements ñ the people involved, the biosafety review procedure, and mechanisms for feedback. These four elements function together to produce environmentally responsible decisions. Establishing and maintaining a functional, effective biosafety system presents management challenges at every step. It requires education and coordination across government ministries, universities and research institutes, private-sector interests, individual scientists, and the public. Significant investments may be needed in training and human resource development, information and communications systems, facilities, and follow-on activities. In facing this task, it is worth bearing in mind that the elements in a biosafety system, and the challenges they present, are interrelated and interdependent. Therefore efforts to strengthen any one part will ultimately strengthen the entire system and the biosafety decisions coming from it.