Abstract : During cardiac arrhythmia, functional reentries may take the form of spiral waves. The purpose of this study was to induce spiral waves by an electrical stimulation of cultured neonatal rat cardiomyocytes using a microelectrode arrays technology. In basal conditions, cardiac muscle cells in monolayer culture displayed a planar wavefront propagation. External electrical impulse trains induced severe arrhythmia and spiral waves appeared. This in vitro generation of spiral wave opens a new way to test the anti-arrhythmic drugs and for strategies at microscopically scale.