Cyber-attacks are a significant threat faced by even the most advanced and efficient grid systems. This paper presents the Risk Assessment (RA) of multi-area load frequency control (MA-LFC) to data injection cyber-attacks (CA). The analysis, carried out from a power system engineers perspective, illustrates a successful stealth attack that can be implemented on the system with minimal system knowledge by injecting false data into the sensor and actuator measurements. A combination of an eavesdropping attack (EDA)and False Data Injection Attack (FDIA) is used in the attack model. An algorithm was developed to study the impact of the attack, and results are presented for a 9-bus system and 39-bus New-England test system. It was observed that the method is robust and can present the risk assessment of cyber-attack in MA-LFC. © 2020 IEEE