Introduction: paraneoplastic syndromes are sets of signs and symptoms affecting cancer patients, which do not depend directly on the tumor. Objective: to describe paraneoplastic syndromes associated with digestive system tumors. Methods: a search for information was carried out in the PubMed/MEDLINE and ScienceDirect databases. The search terms used were: “neoplasias gastrointestinales”, “gastrointestinal neoplasms”, “síndrome paraneoplásico”, “paraneoplastic syndrome”, “sistema digestivo”, “digestive system”, through Boolean operators. Thirty bibliographic references were reviewed. Development: in digestive neoplasms, dermatological syndromes are the most common, and include acanthosis nigricans, seborrheic dermatosis, pruritus, pityriasis rubra, and acrokeratosis of Bazex, among others. Endocrinological (hypercalcemia, hypoglycemia, thyrotoxicosis), hematological (polycythemia, thrombophlebitis, anemia) and neurological (myasthenic Lambert-Eaton syndrome, neuropathy) paraneoplastic syndromes may also appear. Conclusions: the early recognition and diagnosis of dermatologic, endocrine and hematologic paraneoplastic syndromes, of frequent manifestation in the course of gastrointestinal neoplasms, allows a comprehensive care of the oncologic patient and contributes to improve his/her quality of life.