Abstract Microalgae-based processes and products are of great interest to researchers, private companies, and government agencies worldwide due to their broad diversity of uses. However, the current applications are concentrated in single operations. The economical, sustainable, and robust design of microalgae installations requires the total chain integration of energy, mass, and water surplus. Many integration possibilities have been proposed, but rarely developed. In this sense, in this chapter, we expose a compilation of information on process integration applied to microalgae-based systems. First, we provide the reasons why microalgae are exploited, and then we criticize the obstacles that prevent full commercial competitiveness. The core of the chapter is to display the frontier of knowledge about the different possibilities of integration. Finally, a brief discussion of environmental and economic issues impacting microalgae systems is presented.