The objective of the study was to do galactomannan testing in the serum and BAL samples and correlate it with clinical data. The galactomannan testing was done by an immunoenzymatic sandwich microplate assay in 49 patients. Clinical data could not be obtained for nine patients. In the remaining 40 patients, single serum or BAL galactomannan was positive in 14 patients (35%) who had invasive pulmonary aspergillosis (IPA), and galactomannan was negative in 26 patients (65%) who had non-invasive pulmonary aspergillosis (non-IPA). Galactomannan tests were positive in 4 serum samples and 10 BAL samples. The test was negative in 15 serum samples and 11 BAL samples. BAL was the better sample for galactomannan testing, with a p-value of 0.048. Among the 14 patients with IPA and galactomannan positivity, only 2 had growth of Aspergillus, whereas among the 26 non-IPA patients with galactomannan negativity, only one grew Aspergillus. There is statistical significance in fungal culture between the two groups (p-value 0.023). The number of patients undergoing hemodialysis in the IPA group was 3, and all were positive for the galactomannan assay. In the non-IPA group, one patient had undergone hemodialysis and was negative for the galactomannan test. There is statistical significance between the two groups (p-value 0.027). The galactomannan assay must be carefully interpreted along with the clinical radiological findings, type of treatment, and associated cross-reactions.