Spontaneous mechanical activity of 36 segments from the ampullar part of human Fallopian tubes was studied in vitro. The age of the patients varied between 37-64 years. Outer diameter and axial tension were continuously measured at an intraluminal pressure of 5 mmHg (0.67 kPa) and at 10% axial extension. All segments have shown periodic contractions both in diameter and axial tension. The amplitude of the outer diameter contractions was 0.03-0.64 mm, the frequencies were between 1.5 and 7.3 min-1. The amplitude of the axial tension contractions was 1.87-33.2 mN, the frequencies varied between 1.8 and 7.6 min-1. The diameter and axial tension contractions were mostly synchronized. The frequency of the basal rhythm increased with age. Increase of the intraluminal pressure up to 15 mmHg (2.0 kPa) significantly increased the diameter and decreased the amplitude of diameter contractions. Increase in the axial length significantly decreased the outer diameter and the amplitude of diameter contractions; it also increased axial tension, and caused a transitory increase in frequency.