In adult mammals, thousands of new neurons integrate in the olfactory bulb (OB) each day. This process of adult neurogenesis has received a great deal of scientific attention aimed at understanding how mature neural networks withstand neuronal replacement, and medical interest to explore the promise that these cells may be manipulated for brain repair therapies. In the present review, we focus on the mechanisms and consequences of the functional integration of newborn interneurons in the OB network. We first describe the steps of synaptic integration and functional maturation of adult-born interneurons in the OB. We then examine the physiological control of cell maturation and survival. Finally, we explore the potential impact of adult neurogenesis on the function of the OB.