Based on a qualitative research of the case study type, this article aims at establishing Nursing Diagnosis (ND`s) of patients with colorectal neoplasia undergoing chemotherapy treatment considering their altered basic human needs. The project was approved by the Research and Post-Graduation Group of Hospital de Clínicas de Porto Alegre (HCPA) (project number 07-001). The study analyzed 11 subjects starting ambulatory chemotherapy treatment in the Ambulatory Chemotherapy Unit of HCPA. Out of 23 established ND`s, 15 were related to physiological needs, 6 to alterations in protection and safety needs and 2, related to alterations in esteem needs. The collected data led to the conclusion that the most prevalent ND`s are connected with physiological needs, namely: Infection Risk; Sleep Disturbance Pattern; Unbalanced Nutrition: below the body needs; Damaged Tissue Integrity; and, High Risk for Damaged Tissue Integrity. Regarding alterations in protection and safety needs, Anxiety ND was the most prevalent one. At last, the ND`s established from esteem needs were: Disturbed Body Image and Impotence. According to the obtained results, it is possible to reaffirm the importance of the ND as a tool in the nursing care because it can interfere in an efficient, individual and proper way for each kind of problem experience by the patient.