Objectives: To identify the reactions of the venous network and investigate the prevalence and characteristics of these reactions in women with breast cancer during chemotherapy treatment. Methods: It were evaluated 339 records of women undergoing chemotherapy, from 2003 to 2007. Results: During neo-adjuvant and adjuvant treatments (17.1% and 22.4%) the women presented several occurrences, the most common were: external infiltration, pain and alteration in skin color. The neo-adjuvant treatments most often cited were: use of cold packs (2.9%) and subcutaneous application of local glucocorticoid (3.5%), and the adjuvants were: local subcutaneous application of hydrocortisone (3.2%), implementation of external infiltration protocol (6.2%) and use of ice packs (7.1%). Conclusion: The recording of occurrences and the nursing report are essential to supervise the venipuncture sites used during chemotherapy; also it is recommended measuring and record photographically the place of puncture.234552556