Voltage-elicited action potentials (APs) have been reproducibly obtained in Arabidopsis thaliana ecotype col. Excitations pulses (voltage–duration: V–t) were given in the 0- to 18-V and 0- to 35-s ranges, respectively, by two galvanically isolated Pt/Ir small wires inserted through the main vein in the distal part of the leaf. Conventional liquid junction Ag/AgCl electrodes were placed at the zone between leaf/petiole (e1) and a second one on the petiole, near the central axis of the rosette (e2). A typical hyperbolic V–t relationship was obtained. The most excitable plants did have a chronaxy of 0.1 s and a rheobase of 2 V. Although the amplitude of the Aps was highly variable (range 10–80 mV), it was related neither to the intensity nor to the duration of the stimulation pulse: the phenomenon is a typical all-or-none response. The Aps were moving away from the excitation zone and could successively be detected at e1 and then at e2: their propagation speed was 1.15 0.26 mm s21. The absolute refractory period was approximately 20 min and the relative one approximately 80 min. The reproducibility of the voltage elicitation was in A. thaliana col ecotype 91%, with 83% of the APs propagating from the leaf to the petiole. In the Wassilewskija ecotype, 45% of the plants were responsive, with 78% of APs transmitted (propagation speed was 0.76 0.17 mm s21), whereas in the Lansberg erecta ecotype none of the plant tested elicited a voltage-dependent AP.