In sheep, pirenzepine (Pi) blocks muscarinic receptors thus inhibiting the gastrointestinal motility. However, its small doses also evoke the premature phase 3 of the migrating motor complex (MMC). The aim of this study was to specify further the character of stimulatory alterations caused by the drug in non-fasted sheep. The experiments were carried out in four conscious rams with sewn duodenal strain gauge force transducer and duodeno-jejunal bipolar electrodes. Following the control period, 0.15 M NaCl or Pi, at the dose 0.02 mg/kg body weight, were slowly administered into the jugular vein and motor-myoelectric activity recordings were continued until normal motility returned. In the course of most experiments Pi evoked the premature phase 3 preceded by 3-5 min inhibition in non-fasted rams. Its duration in the duodenum was shorter than in the jejunum and the same difference was observed in normal phase 3 of the MMC. Amplitude and duration of the spike bursts forming the premature phase 3 was not significantly different from normal phase 3 of the MMC cycle. The premature phase 3 exhibited a regularly propagating character in most cases, but occurred also in incomplete or disorganized forms. Usually, its character thus closely resembled the normal phase 3 of the MMC. It appears that Pi, at the low doses, triggers the premature phase 3 via the blockade of neuronal M1 receptor subtype that provokes the secondary activation of acetylcholine release. Induction of premature phase 3 by a small dose of Pi resembles the effect observed in monogastric species.