Rubinstein-Taybi syndrome (RTS) is a rare human genetic disorder characterized by mental retardation and physical abnormalities. Many RTS patients have a genetic mutation which has been mapped to chromosome 16p13.3, a genomic region encoding cyclic AMP (cAMP) response element binding protein (CREB) binding protein (CBP). CBP is a transcriptional co-activator that binds to CREB when the latter is phosphorylated and promotes gene transcription. CREB-dependent gene transcription has been shown to underlie long-term memory formation. In this review we will focus on recent findings regarding the biology of CBP and its role in memory formation and cognitive dysfunction in RTS. We will also review the role of CBP in other neurological disorders, including Alzheimer's disease, Huntington's disease and amyotrophic lateral sclerosis. Finally, we will discuss novel therapeutic approaches targeted to CBP/CREB function for treating the cognitive dysfunction of RTS and other neurological disorders.