High-resolution mmWave radar sensors are becoming integral in applications ranging from automotive safety and autonomous driving to people counting, health monitoring of infants and the elderly. Many application encourage the use of multiple sensors to enhance the detection and classification performance. This often leads to a problem of interference from other sensors. In this paper, using multiple FMCW MIMO radar sensors, we intend to investigate the effect of interference on victim in terms of signal-to-interference-plus-noise ratio. To this end, we study three types of interference phenomenon that occurs for the radar sensors operating in a same frequency band, namely “Same slope”, “Similar slope” and “Sweeping slope”. This paper discusses the results that have been generated using Monte-Carlo simulation in MATLAB and further verified on mmWave radar sensors using indoor measurements.