Digestive lesions were observed in 84 of 136 sea turtles (128 Caretta caretta, four Chelonia mydas and four Dermochelys coriacea) stranded in the Canary Islands between January 1993 and December 2001. In the oral cavity ulcerative and necropurulent stomatitis were the most frequently observed lesions, and in the oesophagus ulcerative and fibrinous oesophagitis, and traumatic oesophageal perforation were most frequently observed; all these lesions were mainly associated with the ingestion of fishing hooks. Different histological types of gastritis were observed in 35 of the turtles; necropurulent and fibrinous gastritis were associated with bacterial infections caused mainly by Proteus species, Vibrio alginolyticus, and Staphylococcus species, and larval nematodes of the genus Anisakis were responsible for a form of parasitic gastritis observed in 16 of the turtles. Different histological types of enteritis, including catarrhal, fibrinous, necropurulent and necrotising enteritis, affected 36 turtles; a wide range of Gram-negative and Grampositive bacteria, including Bacillus species, Escherichia coli, Pasteurella species, Proteus species, Staphylococcus species, Streptococcus species and V alginolyticus, were isolated from these lesions. All the cases of necrotising enteritis were associated with intestinal intussusception caused by the ingestion of monofilament fishing lines. Necrotising and/or multifocal granulomatous hepatitis were the lesions most commonly observed in the liver; they affected 29 of the turtles and were associated with Aeromonas hydrophila, Citrobacter species, E coli, Proteus species, Staphylococcus species and V alginolyticus infections. According to the stranding reports and the gross and histological lesions observed, 33 of the turtles had digestive lesions associated with the ingestion of hooks and monofilament lines, and two had lesions associated with the ingestion of crude oil.