AbstractCancer patients' complaints of impaired cognition following chemotherapy are fairly common but poorly documented among adult patients. Neuropsychological testing was used to evaluate current cognitive functioning of 28 stage I and II breast cancer patients (ages 28–54) who had completed 3 to 18 months of adjuvant chemotherapy, from 0.5 to 12 months prior to testing. Effects of drug regimen, length of treatment and level of depression on cognitive functioning were examined. Despite estimated high‐normal pre‐morbid intelligence (mean FSIQ 113) patients scored significantly below age‐, education‐, and gender‐corrected test norms in areas of verbal and visual memory, mental flexibility and speed of processing, attention and concentration, visuospatial ability and motor function. Of patients, 75% scored ‐2SDs (moderate impairment) on one or more test measures. Level of cognitive impairment was unrelated to depression, type of chemotherapy and time since treatment, but was positively related to length of chemotherapy treatment. These preliminary findings suggest that cognitive impairment may follow conventional adjuvant chemotherapy treatment and warrant replication with a controlled and more rigorous longit