We report the growth of highly crystalline GaS tubular structures directly on Ga metal from banana-leaf like structures via a facile catalyst free physical vapor deposition process. GaS microtube arrays with 1.5-2 mu m length were synthesized by promoting the intrinsic layered crystal structure of GaS during thermal evaporation where the thermal stress and interlayer interactions are mostly dominant. We monitored the growth process systematically to build a proper understanding of the formed tubular structures in this layered material. Microstructural analyses indicate that the GaS microtubes start with the formation of ultra-long, uniform banana-leaf like morphology that eventually splits into thinner flakes and starts rolling in nanometer size diameters. Final realization of GaS microtubes happened by the expansion of these intermediate rolled-up layers in their outer diameter by minimizing the strain energy in the system in a self-catalytic growth process. (C) 2013 Elsevier B.V. All rights reserved.