Modern spray requirements are constantly demanding lower flow rates per injector.With this as the motivation, we investigate the use of microelectromechanical system (MEMS) technology to design, fabricate, and characterize a monolithic microscale pressure swirl atomizer. MEMS wet-etch technology is used to form the inlet ports, swirl chamber, and exit orifice in a thin sheet of silicon (Si) by deep reactive-ion etching method. The spray performance of the micro atomizer is experimentally studied using high-speed imaging and optical patternation techniques. The geometrical features of the atomizer, such as number of tangential inlet port Np, width of the inlet port Wp, and diameter of exit orifice Do, are varied to understand their effect on spray performance. The results demonstrate that the exit orifice diameter has a major role in deciding the spray flow rate. However, spray uniformity is primarily determined by the number of inlet ports entering the swirl chamber and their widths. Finally, we show that MEMS technology is capable of producing sprays whose flow rates are nearly 50% of the current state of the art with acceptable atomization quality. © 2019 by Begell House, Inc.