This paper focuses on the effect of addition of a secondary gas jet on diameter and morphology of bicomponent nanofibers produced using the gas jet fibers (GJF) process. In GJF process, a primary turbulent gas jet is used for liquid jet initiation, liquid jet stretching, and drying of the liquid jet into nanofibers. The secondary gas jet is added to provide additional stretching of the liquid jet so that fibers of even smaller diameter can be obtained. The location of the secondary jet in relation to the liquid delivery nozzle is varied to determine an area of influence of the secondary gas jet on fiber diameter and fiber morphology. The radius of the copper loop used to deliver the secondary gas jet is also varied to assess its effect on fiber diameter. The results show almost 100% reduction in nanofiber diameter of bilobal and interpenetrating network type nanofibers with appropriate placement of the secondary gas jet. The additional stretching also creates gradient morphology promoted by incomplete phase separation of the polymers as a consequence of much faster solvent loss. (C) 2017 Elsevier Ltd. All rights reserved.