To assess potential barriers to seeking human immunodeficiency virus (HIV) testing among adults in the United States, data from the 1998 National Health Interview Survey (NHIS) were analyzed. The NHIS is a multistage cluster survey of the United States noninstitutionalized civilian population ages 18 years or older. The 1998 NHIS survey was conducted using the computer-assisted personal interview. Of a nationally representative sample (n = 32,440) of the U.S. noninstitutionalized civilian population, 21,410 (66%) have never been tested for HIV, 9,728 (30%) have been tested, and 1302 (4%) did not complete the survey or refused to answer the question. Among individuals who completed the survey, men (odds ratio [OR]: 1.08, 95% confidence interval [CI] = 1.04, 1,22), individuals ages 50 years or older (OR: 4.01, 95% CI = 3.16, 5.08), or 18-19 years (OR: 2.12, 95% CI = 1.71, 2.63), those who had "up to 11 grade" level of education (OR: 2.16, 95% CI = 1.74, 2.63), those who lived in nonmetropolitan areas (OR: 1.21, 95% CI = 1.14, 1.28), or lived in the Midwest (1.34, 95% CI = 1.24, 1.43) were significantly more likely than their counterparts to have not sought HIV testing. Among individuals who have never been tested for HIV, 58% had no particular reason, 38% felt they were not at risk of contracting HIV, whereas less than 1% feared adverse consequences. The high proportion of adults who never tested for HIV after two decades of HIV epidemic underscores the need for new approaches to fight the spread of HIV infection in the United States.