In industrialized countries with a Western lifestyle, sensitization to perennial aeroallergens is strongly associated with asthma, whereas sensitization to seasonal aeroallergens is closely related to allergic rhinitis. Little is known, however, about the relation between skin test reactivity to aeroallergens and either asthma or rhinitis in mainland China. We studied 10,009 members of 2,544 families in Anqing (China) that were selected on the basis of physician-diagnosed asthma in at least two siblings. Generalized estimating equations were employed to study the association between skin test reactivity to aeroallergens and either asthma or rhinitis. After adjustment for age, sex, intensity of smoking, skin test reactivity to other aeroallergens, and household correlations, sensitization to dust mite was an independent predictor of both asthma (OR = 1.3, 95% CI = 1.1 to 1.5, p = 0.008) and rhinitis (OR = 1.3, 95% CI = 1.0 to 1.8, p = 0.04). Sensitization to mold was significantly associated with asthma (OR = 1.6, 95% CI = 1.1 to 2.3, p = 0.008), and sensitization to silk was an independent predictor of rhinitis (OR = 1.5, 95% CI = 1.1 to 2.2, p = 0.02). Although 46.9% of the study participants were sensitized to at least one allergen, only 3.5% of study subjects reported nasal symptoms consistent with rhinitis. Among asthmatic subjects, 6.2% reported nasal symptoms. Whereas sensitization to perennial aeroallergens was associated with asthma among families of asthmatic subjects in rural China, sensitization to silk was the strongest predictor of rhinitis in this population. Our findings also suggest that allergic rhinitis is far less common among asthmatic subjects in rural China than in asthmatic subjects in industrialized countries with a Western lifestyle.