A registry for Paget's Disease (PD) was created to study the environmental and familial features of this disorder. This study examines the first 202 people enrolled. Those with a family history of PD (20%) suffered earlier deformity and fracture, and tended to have grandparents born abroad. These findings suggest heritage is important in PD; the role of environment remains unclear. Introduction: The New England Registry for Paget's Disease of Bone is a database that was created to explore the distribution and determinants of disease frequency. Methods: Using a case-series design, we explored the association of environmental factors in expression of the disease, comparing those patients with familial Paget's disease to those with sporadic Paget's disease (PD). Results and Conclusions: Analysis of the first 202 patients enrolled in the registry revealed a positive family history (FH) in 41 (20%). Significant findings in this cohort included an earlier age of onset (51 years FH+ versus 59 years FH−, p < 0.05), a trend to a higher incidence of bone deformity (49% versus 33%, p < 0.1), and an increased fracture rate (27% versus 11%, p < 0.05). Persons with a FH of PD were less likely to record the United States or Canada as their grandparents' birthplace (p < 0.01), and sibships tended to be larger (p < 0.05). A history of measles infection, childhood exposure to pets, milk ingestion, year of immigration to the United States, birth order, level of education, and functional status did not distinguish the two groups. The database confirms the high prevalence of familial PD and supports the theory that heritable factors are important in the pathogenesis of this focal disorder of bone metabolism.