Production systems which has more than one assembly line is widely seen in industry. These lines produce same or similar products, and their cycle times are generally considered similar. So, Gokcen et al. (2006) suggested to combine workload of some stations on parallel consecutive lines, in a convenient way, for improving the resource utilization and the efficiency of the production system. This common balancing of more than one assembly line is named Parallel Assembly Line Balancing Problem (PALBP). The major aim of PALBP is to obtain minimum number of stations (or operators). In this paper, a simulated annealing (SA) based approach is developed for PALBP. This paper is built directly on the study of Gokcen et al. (2006). The proposed approach is illustrated with a numerical example and its performance is tested on data set taken from Gokcen et al. (2006). In the computational studies, for 95 test problems, the proposed approach found 47 proven optimal solutions and 6 solutions superior to Gokcen et al. (2006).