This paper presents a procedure for robust two-degrees-of-freedom PID synthesis based on a non-convex optimization problem considering the H-2 and/or H-infinity guaranteed costs of the closed-loop transfer matrix as objective functions and constraints together with robust regional pole placement. The uncertain system can be represented by multiple, polytopic or affine parameter-dependent models. The efficiency of the proposed synthesis procedure is illustrated by examples. (c) 2007 Elsevier Ltd. All rights reserved.