This paper presents an investigation of joint clearance influences on the mechanism path generation and transmission angle. Joint clearance was treated as a massless virtual link and mathematical expression of its motion was obtained by using Lagrange's equation. Genetic Algorithm (GA) approach was used to describe the direction of the joint clearance relative to input link's position and also to implement the optimization of link parameters for minimizing the error between desired and actual paths due to clearance. Four-bar path generator was used as an illustrative example. The main advantages of the proposed approach are its simplicity of implementation and its fast convergence to optimal solution, with no need of deep knowledge of the searching space. (C) 2008 Elsevier Ltd. All rights reserved.