This study presents a particle swarm optimization (PSO) algorithm for beam-slab layout design. Design of beam-slab layouts is considered a heuristic task rather than an algorithmic task since its process cannot be written as an algorithm. In this study, this design task is expressed as an optimization problem. This is done by establishing appropriate objective and constraint functions based on selected suitable engineering consideration. The obtained optimization problem is then solved by a simple PSO algorithm. PSO is a rather new optimization method that is inspired by the flocking behavior of fishes and birds. Recently, it has gained popularity because its algorithm is simple and there has been evidence of its excellent performance. To employ PSO in solving the optimization problem that represents the beam-slab layout design problem, a suitable coding scheme for beam-slab layouts is used. Since the beam-slab layout design problem deals with a discrete search space of beam-slab layouts, a discrete version of PSO is employed in this study. The proposed PSO algorithm is tested by solving the beam-slab layout design problem of a rectangular floor. The validity of the proposed algorithm is observed from the obtained results.