In mammalian primary visual cortex (V1) two major modes of representing orientation information have been described. In rodents V1 neurons with different orientation selectivities are intermingled in a salt-and-pepper fashion, whereas in all primates studied so far they areorganized in orientation pinwheel maps. What are the factors that influence the V1 functional architecture in a species? Is this difference in representation due to constraints of the smaller brain size in rodents or can pinwheels also be found in primates with rodent-sized brains? To address this question, we performed intrinsic optical signal imaging in the mouse lemur (Microcebus murinus), one of the world’s smallest primates (~60 g), with a brain size comparable to the rat. Our results show that mouse lemur V1 contains robust orientation pinwheel maps with properties comparable to other primates and adheres to a common design framework.