Electrospraying has been recognized as an important technique for the production of microparticles for pharmaceutical applications. Nevertheless, the produce of poly (d,l)-lactide-co-glycolide (PLGA) microspheres with a desired size distribution remains a challenge. We conducted an empirical study, based on a fractional orthogonal design, to optimize the size distribution of electrosprayed particles. The influence of different processing factors, including PLGA concentration in the solution, volumetric flow rate of the solution, travel distance between the needle tip and the collection, voltage applied to the polymer solution, size of the needle, and type of solvent on the electrospraying of polymeric microparticles was investigated. After electrospraying, the size distribution of the PLGA particles was characterized and analyzed. Among the selected factors, the type of solvent used was the principal factor affecting the particle size of electrosprayed microspheres. Hexafluoro-2-propanol (HFIP) electrosprayed microparticles with the smallest diameter. However, hollowed particles could be seen among these microspheres. Dichloromethane (DCM) was found to electrospray microspheres with a fairly spherical geometry, while trichloromethane (TCM) electrosprayed particles with relatively rougher surfaces. Finally, the particle size of sprayed microspheres decreases somewhat with the polymer concentration and travel distance.with electrospraying, nevertheless, the optimization of the spraying procedure has been based on a time-consuming trial-and-error process.In past three decades, PLGA has been one of the most attractive polymeric materials used to manufacture devices for drug delivery and tissue engineering applications [15]. PLGA is biocompatible and biodegradable, possesses a wide range of erosion times, has tunable mechanical strengths, and most importantly, is a FDA approved polymer. Crystalline PGA, when co-polymerized with PLA, reduces the degree of crystallinity of PLGA, and as a result, increases the rate of hydration and hydrolysis. As a rule, a higher content of PGA leads to quicker rates of degradation, with an exception of 50:50 ratio of PLA/PGA, which exhibits the fastest degradation. A ratio of 50:50 PLGAs have been extensively studied for the development of devices for controlled delivery of small molecule drugs, proteins and other macromolecules in commercial use and in research [16].An empirical study, based on a fractional orthogonal array design, was completed to investigate the effect of different processing factors on the size distribution of electrosprayed particles. 50:50 PLGA materials were selected. Experiments were carried out on an electrospraying setup consisting of a syringe and needle, a ground electrode, and a high voltage supply. After electrospraying, the particle size and morphology were characterized by a scanning electron microscope. A fractional orthogonal was designed based on a design matrix proposed by Dr. Genichi Taguchi [17]. It allows one to examine a selected subset of combin...