Green tea is widely known for its beneficial biologic effect and there have been some reports on the beneficial effect on the reproductive system. There have however been no reports on green tea effects on uterine contractility. This study is therefore aimed at the investigation of green tea extract on the amplitude and frequency of uterine contractility. Green tea bags were macerated in boiling water for 5 min and concentrated to dryness. The extract (0.33 -1333.21 µg/mL) was tested on the isolated mouse uterus. The contractility parameters investigated included spontaneous contraction, oxytocin (60 pg/mL) induced contraction and high KCl (80 mM)-induced contraction. High resolution mass spectrometric (HRMS) determination of secondary metabolites was also performed on the extract. The extract inhibited both the amplitude and frequency of uterine contractility studied, however minimal inhibitory effect was observed with KCl-induced contraction. The HRMS analysis revealed the presence of twenty-five (25) significant compounds, 23 of which were identified and 2 were unknown. Compounds were observed to belong to a diverse range of phytochemical classes including pteridine, flavonoids, cyclitols, and coumarins, with the majority of detected compounds belonging to the flavonoid class. The results obtained in this study have shown that green tea extract inhibits uterine contractility possibly due to the presence of the flavonoids, and through interaction with calcium and/or prostaglandins.