Background: Early diagnosis of systemic fungeal infections like Aspergilosis is a main problem in patients, especially with malignancy, pulmonary TB, Asthma, and COPD. In this study pulmonary tuberculosis and chronic obstructive pulmonary disease are studied as the predisposing disorders for aspergilosis, and this was because of the high prevalence of these two disorders in Iran and high mortality in association with aspergilosis. Materials and methods: Indirect hemagglutination assay (IHA) was used for measuring the antibody titers against aspergillus fumigatus, mainly of IgM type. Sheep red blood cells coated with aspergillus fumigatus antigens were used as the antigen suspension, for detection of the agglutination in titers between 1:10 to 1:1280. 58 patients, including 32 with TB and 26 with COPD had entered this study. For each patient in the case group, a person was matched as the control group. Obtained sera were kept frozen until the time for examinating all of them. Results: Test results for the TB group were so: 34% 1:1, 15.5% 1:10, 22% 1:20, 9% 1:40, 9% 1:80, and 9% 1:160. For the COPD group these results were achieved 38.5% 1:1, 27% 1:10, 4% 1:20, 19% 1:40, 7% 1:80, and 4% 1:160. From each control group one person had showed titer of 1:20, who had undergone further studies considering the probable previously aspergilosis. According to the kit instruction and by evaluation of cut off point, the positive titer was considred 1:20 or more. So, 50% of the patients with TB and 34% of the patients with COPD were considered positive. Conclusion: Acquired deficiency in immune system among patients with TB was known responsible for special distribution of positive test titers, and IHA is proposed as a sensitive method,as well as cheap and easy, to be used in epidemiologic studies.