Bridges are omnipresent in every society and they affect its human, social, ecological, economical, cultural and esthetic aspects. This is why a durable and safe usage of bridges is an imperative goal of structural management. Measurement and monitoring have an essential role in structural management. The benefits of the information obtained by monitoring are apparent in several domains. First, it helps to improve and enlarge the knowledge concerning structural behavior and makes accurate calibration of numerical models describing and predicting this possible behavior. Thus, project and construction can be optimized in structural and economical aspects. Second, permanent monitoring can give early indications of structural malfunction. In this way, safety measures can be considered in time, and intervention on the structure can be performed immediately and with minimal economic losses. The lifespan of a bridge starts with construction. Followed by testing of the bridge and most importantly the service period. During service, the structure may be refurbished, strengthened or enlarged, according to necessities. Finally, at the end of usage, the bridge can be dismantled. Monitoring during each period of the bridge lifespan is important and can give rich information allowing a better understanding of structural behavior and consequently better planned and less expensive management. In this paper, a brief introduction to the monitoring process is firstly presented. Then, the importance of the monitoring of each period of a bridge's life is examined step by step, and illustrated with a relevant practical application examples.