Effects of the spin line temperature and melt index of polymer on fiber formation by the melt-electrospinning process have been studied. Employing four levels of primary heating temperatures and two levels of secondary heating temperatures provided the necessary temperature profiles. Cooling time was altered through variation in tip-to-collector distance. Effects of the polymer melt index were also investigated using two types of poly(propylene) with different melt index values. Changes in diameter and structure of the electrospun fibers were then observed using scanning electron microscopy and differential scanning calorimetry. It is worth to note that providing enough cooling time in the spin line is effective in producing finer fibers. However, introducing the higher heating temperature in the spin line adversely affected fibrous shape formation. POLYM. ENG. SCI., 49:391-396, 2009. (C) 2008 Society of Plastics Engineers