A new micro-fluidic biosensor array for fast online adherent cell monolayer analysis during cell proliferation and stimulation was developed. Quartz crystal resonators and impedimetric sensor responses were analysed by means of impedance spectroscopy. Time-lapse light microscopy was employed for visual characterization of the cells. Four independent units embedded within the same device allow parallelized cell cultivation. An external flow injection system provides automated and parallelized media feed as well as overpressure regime in the system. Thin-film deposition techniques were applied for sensors fabrication. New dedicated sensor interface electronics were developed to allow fast and parallelized spectra acquisition on 32 sensors. Madin-Darby Canine Kidney cells were cultivated in the biosensor array. The cell behavior during cell proliferation and stimulation was analyzed online. It is believed that in the future, the new biosensor array can be successfully employed as a tool supporting standard techniques employed in molecular cell biology for the study of that complex system of communication that governs basic cellular activities and coordinates cell actions.