To identify the correlation between the house dust mite-specific lymphocytes proliferation and other clinical parameters and clinical features, we conducted a lymphocytes stimulation test in 37 patients with atopic dermatitis. A total of 12 patients showed positive reactions (positive patients) and 25 showed no reaction (negative patients). Both the number and percentage of peripheral blood eosinophils were significantly lower in positive patients than in negative patients. Stimulation index measured by lymphocytes stimulation test showed no correlation with the total IgE level, nor the number and percentage of eosinophils. Stimulation index weakly correlated with mite-specific IgE-RAST scores both in positive patients and in negative patients. Only in positive patients, stimulation index weakly correlated with the severity measured by the clinician score method. Three out of four positive patients showed an increased stimulation index in accordance with increased clinician scores during their clinical course. These results could suggest that, in positive patients, a house dust mite allergy might be an active cause that exacerbates clinical symptoms at the time of their clinical course. Therefore, the stimulation index of the lymphocytes stimulation test might become one of the effective parameters that reflect the involvement of a house dust mite allergy in adult atopic patients.