[en] Nuclear spectroscopy instruments are important tools for nuclear research and applications. Several types of nuclear spectrometers are being sent to numerous laboratories in developing countries through technical co-operation projects. These are mostly sophisticated systems based on different radiation detectors, analogue and digital circuitry. In most cases, they use microprocessor or computer techniques involving software and hardware. Maintenance service and repair of these systems is a major problem in many developing countries because suppliers do not set up service stations. The Agency's Laboratories at Seibersdorf started conducting group fellowship training on nuclear spectroscopy instrumentation maintenance in 1987. This article describes the training programme