Myrtle or Myrtus communis L. (M. communis L.) belongs to the Myrtaceae family. It is a widespread shrub in the Mediterranean area. The objective of this study is to determine the polyphenol content of the methanol (ME), chloroform (CHE) and ethyl acetate extract (EAE) of myrtle leaves and to investigate their gastrointestinal antimotility, antidiarrhoeal and intestinal antisecretory effects in mice. The plant powder was extracted with different solvents of increasing polarity to obtain the above different fractions. The extracts were stored at 4 C° until use. The content of total phenols, flavonoids and tannins of the different extracts were determined using spectrophotometric methods. The antimotility activity was evaluated using gastric emptying and intestinal transit phenol red method. Atropine (1mg/kg i.p.) was used as a positive control. The antidiarrhoeal and antisecretory effects were determined using castor oil. Three different doses (50, 250 and 500 mg/kg p.o.) were used with all the tested extracts. Loperamide (5 mg/kg p.o.) was used as a positive control. Finally, the acute toxicity of the plant extracts was performed according to the Organization of Economic Cooperation and Development (OECD) method at 2 single doses (2 and 5 g/kg p.o.). The results revealed that M. communis L. leaves extracts are rich in polyphenols. The different extracts dose dependently decreased the gastric emptying and the intestinal transit. All extracts also showed significant and dose dependent inhibition of diarrhoea and intestinal secretion. M. communis L. extracts showed antimotility, antidiarrhoeal and antisecretory activities in mice, which may provide scientific support of the folkloric medication with this plant against diarrhoea.