This paper proposes an optimisation technique based on genetic algorithms for the determination of the cutting parameters in multi-pass machining operations by simultaneously considering multi-pass roughing and single-pass finishing operations. The optimum machining parameters are determined by minimising the unit production cost of converting a cylindrical bar stock into a continuous finished profile involving seven machining operations; with each operation subject to many practical constraints. The cutting model developed for each machining operation is a non-linear, constrained problem. Experimental results show that the proposed technique is both effective and efficient.