Cellular processes are mechanisms carried out at the cellular level (within or among more than one cell interactions) that are aimed at guaranteeing the stability of the organism they comprise. The investigation of cellular processes is key to understanding cell fate, understanding pathogenic mechanisms, and developing new therapeutic technologies. Microfluidic platforms are thought to be the most powerful tools among all methodologies for investigating cellular processes because they can integrate almost all types of the existing intracellular and extracellular biomarker-sensing methods and observation approaches for cell behavior, combined with precisely controlled cell culture, manipulation, stimulation, and analysis. Most importantly, microfluidic platforms can realize real-time in situ detection of secreted proteins, exosomes, and other biomarkers produced during cell physiological processes (adhesion, differentiation, migration, apoptosis, and cell-to-cell communication), thereby providing the possibility to draw the whole picture for a cellular process. In addition, these can be used to study the process of cell or tissue response to changes in the microenvironment (drugs, physical signals, or types and quantities of surrounding cells). Owing to their advantages of high throughput, low sample consumption, and precise cell control, microfluidic platforms with real-time in situ monitoring characteristics are widely being used in cell analysis (cellular heterogeneity analysis, cell sorting, and cellular marker detection), disease diagnosis, pharmaceutical research, and biological production. This review focuses on the basic concepts, recent progress, and application prospects of microfluidic platforms for real-time in situ monitoring of biomarkers in cellular processes. This article is protected by copyright. All rights reserved.