This study examined ever and current asthma diagnosis among persons in same-sex relationships (SSRs) using data from the pooled 1997-2004 National Health Interview Surveys. Among SSRs, 13.5% of men and 14.3% of women reported ever diagnosis of asthma, compared to 7.6% and 10.2% opposite-sex relationship (OSR) men and women. SSRs had higher rates of smoking, stress, and among women, obesity. In regression analyses, male SSRs had a significantly elevated risk of ever asthma diagnosis (adjusted OR = 1.51), while 12-month asthma was elevated among SSR women (adjusted OR = 2.48). SSRs may be at higher risk for asthma due to a spectrum of risk factors.