Mixtures of magnesium acetate tetrahydrate ((CH 3COO) 2Mg·4H 2O), ammonium tungstate tetrahydrate ((NH 4) 6W 7O 24·4H 2O), and poly(vinyl alcohol) with the molecular weight of 72,000 were electrospun through a +15 kV direct voltage to form fibers on ground flat aluminum foils. The electrospun fibers of 1.5, 3.0, and 4.5 mmol of each starting material containing 1.3 g poly(vinyl alcohol) were further calcined at 500-700 °C for 3 h constant length of time. At 500 and 600 °C calcination, both monoclinic and anorthic phases of MgWO 4 particles with different sizes connecting as fibrous assemblies were detected. Upon increasing the calcination temperature to 700 °C, only monoclinic phase of facet nanoparticles interconnecting along the fibrous axes with 4.19 eV indirect band gap and 461 nm photoemission was synthesized. In the present research, formation of MgWO 4 molecules as well as nucleation and growth of nanoparticles was also proposed. © 2012 Elsevier B.V. All rights reserved.