Previous studies have indicated that vitamin D deficiency is widespread among immigrants and refugees. This study sought to determine the prevalence of vitamin D deficiency among a large and diverse cohort of refugees in Massachusetts to assess its significance for routine refugee health screening of refugees. 25-hydroxyvitamin D levels for 2,610 refugees screened between 2007 and 2009 were used to estimate vitamin D status and to examine the relationship between deficiency or insufficiency and age, gender, regional origin, and season of testing. Among those tested, 78 % were either vitamin D insufficient or deficient. Insufficiency or deficiency was most prevalent in refugees from the Middle East (89 %) and lowest in those from the Caribbean (59 %). Risk was higher among women than among men from some regions, such as the Middle East, but not others. For women, the likelihood of deficiency increased with age, while for men, the likelihood of deficiency was similar for preschool children and men at the height of their working years. The high overall prevalence of vitamin D deficiency suggests that empiric supplementation or treatment may be preferred to testing until more is known about the long-term epidemiology of vitamin D deficiency and its consequences.