AA6061 aluminum alloy is widely used for fabrication of light weight structures requiring a high strength to weight ratio in aerospace, naval, rail and automotive industries. As compared to the traditional fusion welding processes which are commonly used for joining structural aluminum alloys, friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. In view of this, the present work proposes an experimental investigation, to analyze the effect of welding parameters such as welding speed, tool rotational speed and tool profile on welding strength. The experimental architecture is planned as per Taguchi's L9 orthogonal array so as to extract maximum information with minimum experimental runs. The study revealed that welding speed is an important parameter for the variation of tensile strength. © 2015 Elsevier Ltd.