For reinforced concrete (RC) structures located in a marine environment it is important to consider the effects of this environment on their long-term performance. In this paper, a time-dependent structural reliability analysis method of RC bridge slabs taking the hazard associated with airborne chlorides into consideration is proposed. Also, a procedure to obtain the failure probabilities of RC bridge slabs in a marine environment updated by Sequential Monte Carlo Simulation (SMCS) is indicated. Using SMCS, multiple random variables related to observation information can be updated simultaneously. The effects of marine environment, inspection results, and the number of inspections on the updated estimates of bridge slab reliability are discussed. © 2010 Taylor & Francis Group, London.