Since the 1980's, women treated for breast cancer are reporting moderate cognitive impairments during and after chemotherapy. These cognitive impairments may be related to chemotherapy but also to hormone therapy, psychological distress, fatigue... This work is a critical review of the literature, which reports types of impairments, frequency, severity, causes and mechanisms involved in this issue. It also provides an update on potential moderators factors, which may be associated with mild cognitive impairments and various tools for their assessment used in the studies. These studies--selected between 1997 and 2008--show that cognitive impairments are frequently reported by patients with breast cancer but that the mechanisms are still poorly understood and that the methods of assessment are very heterogeneous and difficult to compare. This review indicates that future studies should include more homogenous patient groups, be longitudinal, use more sensitive and specific assessment tools and control moderators factors that play a role in impairment in cognitive function.