In this article, the lap joint of acrylonitrile butadiene styrene and polycarbonate is produced by submerged friction stir welding. The objective of this research work is to investigate the effect of welding parameters (rotational speed, traverse speed and plunge depth) on tensile strength. Maximization of weld strength (19.2 MPa) is achieved at a rotational speed of 1500 r/min, traverse speed of 40 mm/min and plunge depth of 1.0 mm. The macrostructure morphology and microstructure are analyzed using the optical microscope and scanning electron microscope. The major defects of the joints are cracks, pores and voids, which are the main reasons for decreasing the tensile strength.