Aim: To elucidate the characteristics of patients with asthma who have specific IgE responses to inhaled allergens detected by ImmunoCAP, which is not detectable by MAST-26. Methods: A total of 168 patients with adult asthma who reside in the Kanto region were recruited. Levels of total serum IgE and allergen specific IgE antibodies towards 14 common inhaled allergens (MAST-26) were measured. Among these samples, 48 patients with no detectable allergen-specific IgE (group A) and 44 patients with strong sensitization to Dermatophagoides farinae (group B) were selected for further assessment of their sensitization to inhaled allergens such as cockroach and moth using ImmunoCAP. Results: In group A, ImmunoCAP detected specific IgE responses to some inhaled allergens in 27.1% of the patients. The strongest predictive factor for the presence of allergen-specific IgE responses detected by ImmunoCAP was elevated levels of total serum IgE (p = 0.0007). In group B, the presence of IgE responses specific to cockroach or moth by ImmunoCAP were found in 27.8% or 52.3% of the patients, respectively. The predictive factor for the presence of these positive IgE responses was also elevated levels of total serum IgE (p=0.0003). Conclusion: Asthma patients with no detectable specific IgE responses to any inhaled allergens by MAST-26 may be still sensitized to common inhaled allergens, including cockroach and moth. Thus, the presence of allergen-specific IgE responses may be re-assessed by ImmunoCAP in patients with asthma, especially when patients have higher levels of total serum IgE .