Objective This study aimedto evaluate the influence of nutritional status on the quality of life of a cohort of cancer patients submitted to chemotherapy. Methods Patients receiving chemotherapy for the first time in a University Hospital in Pelotas (RS), Brazil, were evaluated prospectively. Their nutritional risk was determined by the Patient-Generated Subjective Global Assessment scores and their quality of life by the World Health Organization's quality of life questionnaire, administered at the beginning and end of the study. Results One hundred and forty-three patients were studied, 76.2% being females. The prevalence of malnutrition at baseline was 14.0%. The present study found that malnourished patients had a poor quality of life. The nutritional risk of 41.6% of the patients increased after chemotherapy. A significant association was found between the presence of symptoms and increased nutritional risk (p<0.001). Additionally, there was a significant negative correlation between physical domain and nutritional risk scores, showing that quality of life increases as nutritional risk decreases. Conclusion Nutritional risk is inversely associated with quality of life in cancer patients after chemotherapy. Early nutritional interventions could minimize the side effects of treatment with a positive impact on quality of life.