Introduction: The inaccessibility to early parenteral nutrition therapy (NPT) or delayed administration, by a large part of the Brazilian population with gastrointestinal cancer, has a disastrous consequence for the tertiary level of health and fundamentally for the patient due to worsening of its clinical state and tolerance to oncological treatment generating a functional and emotional dependence, reflected in a decrease in their Quality of Life. Currently, 20% of the deaths of cancer patients are secondary to malnutrition, since it influences energy expenditure in a heterogeneous manner. This study aimed to recognize the nutritional repercussions of NPT in patients with gastrointestinal cancer. Methods: This was a longitudinal and quantitative study performed in hospital institutions in Fortaleza, Brazil, comprising 212 patients with cancer of the gastrointestinal tract undergoing NPT. The research was carried out in three phases (I, II and III). In the phase I was performed Global Subjective Nutritional Assessment (ANSG), determination of the Karnofsky Performance Status Scale (KPS) to assess the quality of life, data referring to the fasting time from the prescription of the therapy to its initiation, type of NPT administered and intercurrent in its infusion, in addition to serum lymphocyte and albumin dosage for the evaluation of immunological competence. In Phase II a PPH (Health Promotion Program) was applied in the conscious and familiar patients, from educational actions on NPT. The phase III occurred after 10 uninterrupted TNP pockets where new KPS were determined and new data were collected. It was SPSS software, paired t-test and significance level (p < 0.05). Results: The results showed that 77.67% of the oncology patients had started the NPT severely malnourished and almost half of them still remained approximately 6 to 10 days without any nutritional support until the beginning of NPT. The NPT reduced the risk of complications in patients when it increased the immunological competence of 78.21% and improved the Quality of Life, in functional aspect, raising the KPS = 40 of 76.78% of the patients to KPS = 70, making them able to self-care. The lack of knowledge of NPT was reported by 79.41% of the conscious patients, who presented fear and sadness, replaced after educational actions, by feelings of hope and confidence associated with the improvement of thirst, hunger and weakness. The NPT indices with interruptions were 53.65%, followed by lack of data regarding nutritional status in patients' charts. Conclusion: It was concluded that NPT had a positive impact on patients with improvement in their clinical status and quality of life, but its use in Brazil has not yet been satisfactory and immediate even when the alarming numbers of malnutrition in patients with gastrointestinal cancer are confirmed and your need is essential.