This paper describes the design and implementation of an automatic hydraulic circuit design system using case-based reasoning (CBR) as one of the successful artificial intelligence paradigms. The domain of case-based reasoning and hydraulic circuit design are briefly reviewed. Then a proposed methodology in automatic circuit design and learning with the use of CBR is described. Finally an application example has been selected to illustrate the usefulness of applying CBR in industrial hydraulic circuit design with learning. © 2011 Springer-Verlag.