The closure of the cod fishery in Newfoundland and Labrador has had dramatic social and economic impacts on fishing communities in the province. Following a limited closure in 1992, a more extensive closure followed in 1994, which is still in force today, although income support provided to displaced fishery workers ended in 1999. A population-based study was conducted in 2004/2005 using 7 different sources of administrative and survey data to investigate a range of social, demographic, and health changes in fishing communities affected by the closure of the cod fishery from the period 1991 to 2001. Findings of this study extend our understanding of the impact of the fishing moratorium in Newfoundland. This article also presents both the challenges to and opportunities for using administrative and survey data to explore the impact of the fishery closure on the health and well-being of Newfoundland fishing communities. One of the most significant challenges to using administrative and survey databases was the inconsistencies in how communities were identified across the various databases. Although not without limitations, administrative data is a cost-effective means to explore the impact of socioeconomic change on a population's health status.