Risk based inspection (RBI) planning for engineering systems is considered. Due to difficulties in formulating computationally tractable approaches for RBI for systems, most procedures hitherto have focused exclusively on individual components or have considered system effects in a very simplified manner only. Several studies have pointed to the importance of taking systems effect into account in inspection planning. Especially for large engineering systems it is not possible to identify cost optimal solutions if the various types of functional and statistical dependencies in the systems are not explicitly addressed. Based on new developments in RBI for individual components, the present paper presents an integral approach for the consideration of entire systems in inspection planning. The various aspects of dependencies in the systems are presented and discussed, followed by an introduction to the decision problems encountered in inspection and maintenance planning of structural systems. It is then shown how these decision problems can be consistently represented by decision theoretical models. The presentation of a practical procedure for the inspection planning for steel structures subject to fatigue concludes the paper.