Maintenance is a core activity that ensures the safe, reliable, and cost-effective operation of nuclear power plants throughout their expected lifetimes. This publication collates knowledge and insights from experts from various Member States and identifies general good practices - rather than specific examples - that maintenance managers and personnel can adopt to promote consistently high performance in maintenance. It provides guidance to help navigate some common challenges, such as retaining a highly skilled and committed workforce, optimizing maintenance programmes and efficiently overseeing suppliers and additional staff. It also examines the fundamental aspects of maintenance, such as managerial approach to conducting maintenance activities; the planning and control of maintenance activities with a focus on contractor oversight; the management of documentation and personnel skills; the use of key performance indicators; and the conduct of benchmarks.