Rapidly growing population of the world increases the demand for clean and freshwater. Solar desalination is a simple and environment-friendly process adopted for the conversion of saline and brackish water into potable drinking water. The solar desalination processmainly depends on the system design, operational and climatic conditions and is improved by many methods such as incorporating energy storage material, wickmaterials, and reflectors. The simple and widely accepted solar desalination system is of solar still. The performance of solar still is highly influenced by various factors such aswater depth, basin materials, transparent glass angle, water-glass temperature difference, and absorber area. Moreover, the productivity of freshwater varies according to system design features and technical competence of the system. The purpose of this chapter is to explore the basic theoretical method used for the evaluation of a simple solar desalination system performance. This chapter also presents a case study to investigate the effect of few design and operational parameters on the performance.