Una spina nel cuore, internationally released as A Thorn in the Heart, is a 1986 Italian romance-drama film directed by Alberto Lattuada. It is loosely based on the novel with the same title by Piero Chiara.
Guido, a young man with a gambling problem, falls in love with a mysterious girl named Caterina. After a torrid affair, Caterina leaves Guido who then looks into her past and discovers she has had many lovers.