Structural health monitoring (SHM) is a field in constant advancement, and data acquisition (DAQ) devices are commonly employed in measurement platforms for SHM systems, allowing cost reduction when compared to other instruments and the development of more versatile signal acquisition systems. One problem observed in such devices that can affect the performance of monitoring systems is the effect of crosstalk, which is the interference between the channels of a data acquisition device. This interference, even if apparently small, can hinder the detection of incipient structural damage, which is the objective of SHM systems. The interest of this study lies in the effects of crosstalk in monitoring systems based on the acoustic emission damage detection method, using piezoelectric transducers. In this method, the source of acoustic emission represents the adverse event, or damage, to be detected. Experiments were carried out on two physically separated aluminum plates, in order to ensure that interferences observed in the measurements are due to crosstalk, and a multiplexed DAQ device was used to perform signal acquisition. Obtained results indicate that crosstalk can be significant in these monitoring systems and may lead to false positives regarding the presence of damage in the monitored structure. Furthermore, they also indicate that crosstalk is dependent on the sampling rate used on the data acquisition device, being directly proportional to it.