This paper presents an analysis and synthesis method for a certain type of geared four-bar mechanism (GFBM) for which the input and output shafts are collinear. A novel analysis method is devised, expressions for the transmission angle are derived and charts are prepared for the design of such mechanisms. It is observed that the GFBM considered is inherently a quick-return mechanism. Large time ratios can be obtained with acceptable force transmission characteristics. During the working stroke, approximately constant angular velocity at the output link is observed. For the type of GFBM analyzed, direction of rotation of the input link affects the force transmission characteristics. (C) 2010 Elsevier Ltd. All rights reserved.