Ultrafine composite fibers made from poly(vinyl alcohol) (PVA)/tin glycolate — a moisture-stable tin oxide containing compound — were prepared by a combined sol–gel processing and electrospinning technique. These fibers were subsequently converted to ultrafine tin oxide fibers by calcination treatment, with the aim of producing tin oxide fiber with a high surface area-to-mass ratio and a high specific conductivity value. The acidity of spinning solution plays an important role to the morphology and size of the obtained fibers. The average diameters of the obtained composite fibers were in the range of 87–166nm. It was found that the ultrafine tin oxide fiber showed the high conductivity value of 1.59×10 3 Scm −1 at calcinations temperature of 600°C, and the BET surface area was in a range of 71 and 275m 2 g −1 . Moreover, the effect of calcinations temperature on the phase and the size of the tin oxide fibers were investigated in this study.