Pharmacological therapy targeting the HER2 protein is one of the major breakthroughs in the treatment of cancer patients overexpressing HER2 who have increased survival rates. Despite improved survival, it is important to determine the less frequent adverse effects in order to tailor treatments more personalized to the patients’ features. The possible impact of cancer treatments on cognitive functions is huge, and the effects of anti-HER 2 therapies on this issue have not been reviewed and are the objective of this study. Analysis of PubMed, Scopus, Cochrane library and Web of Science databases revealed six studies performed in breast and serous uterine cancer patients analyzing cognitive function under chemotherapy regimens including anti-HER2 drugs. Four of these studies reported small to significant worsening of cognitive function following chemotherapy regimens containing trastuzumab (the most widely used anti-HER2 drug). In neoadjuvant settings, and in breast cancer patients, treatment with the new anti-HER-2 drug trastuzumab emtansine seems to induce less cognitive impairment than therapeutic regimens containing chemotherapy and trastuzumab. Acute administration of trastuzumab induced cognitive impairment in gastric cancer mice models, confirming its ability to alter cognitive function in patients. More studies analyzing the impact of anti-HER2 therapy on cognitive function are necessary at preclinical and clinical levels in order to personalize pharmacological treatment and offer cancer patients a better quality of life.