Here we discuss the significance of brain enlargement in avian and non-avian theropods in the context of the evolution of powered flight and overall cognitive ability. We suggest that the most important neurological evolutionary trends in Jurassic to Cenozoic birds are probably mostly related to sensory integration and cognition than to flight adaptation. However, although some skeletal specialisations for flight may have affected overall brain enlargement, others, such as the development of the telencephalic wulst region (involved in integration of visual stimuli) may be related to those specialisations.