The viscosity of As2Se3 glass within the hot zone region of the fiber drawing process was estimated using the actual temperature distribution and standard continuum mechanics equations for a linear viscous material. The obtained values for the shear viscosity lie between 10(3) and 10(6) Pa.s and are in good agreement with those extrapolated from bending and penetration tests at a lower temperature. In our condition, neck-down region is to be found almost independent on the drawing rate or on the fiber tension.