Abstract. The objective of this study was to 1) assess the incidence of strongyloidiasis in the United States, 2) evaluate demographic and regional associations, and 3) identify comorbid conditions as risk factors for death. A population-based case-control study was performed by using mortality data during 1991-2006. We identified 347 strongyloidiasis deaths (0.79 per 10 million deaths, 14-29 deaths per year), which decreased slightly over time. Deaths occurred primarily among older (median age = 66.0 years), white (57.6%) and Hispanic (22.2%) men (69.2%), residing in the Southeastern United States (49.3%). Associated health conditions included chronic obstructive pulmonary disease (28.7%, odds ratio [OR] = 4.0, 95% confidence interval [CI] = 3.0-5.4) and infection with human immunodeficiency virus (12.5%, OR = 4.6, 95% CI = 2.7-7.9). Strongyloidiasis deaths in the second half of the study period (1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) were less likely to be associated with chronic obstructive pulmonary disease (19.4%, OR = 1.2, 95% CI = 0.7-1.9), but continued to be associated with human immunodeficiency virus infection (12.9%, OR = 2.8, 95% CI = 1.3-6.0). Early detection and treatment of at-risk patients with latent strongyloidiasis infections is needed to reduce strongyloidiasis mortality.