Microalgae and cyanobacteria convert light energy and inorganic nutrients into biomass that can be used as a source of commercial bioproducts like pharmaceuticals, biofertilizers, biofuels, biopolymers, cosmetics, and food products for humans and animals. However, practical issues need to be addressed before scaling up from laboratory to mass production of algal biomass. The main bioengineering items that determine the performance of microalgae production systems and photobioreactor designs are addressed in this chapter. Trends in microalgae mass production facilities are examined by analyzing each component’s specialized functions. Recently proposed technologies, not only for photobioreactors but also for their complementary and service devices, are concisely referred to. Therefore, a multidisciplinary team of engineers and scientists should analyze novel microalgae production systems or photobioreactors to design, calculate, and implement the best solution for a specific bioprocess or application.