ABSTRACT Background: Pulmonary aspergillosis, caused by Aspergillus species, is a significant concern among patients with chronic respiratory diseases, particularly those with underlying immunosuppressive conditions. Material and method: This prospective observational study was conducted at Guru Nanak Dev Hospital, Amritsar, involving 150 suspected cases. Patients were categorized as "proven," "probable," and "possible" invasive aspergillosis (IA) based on clinical, radiological, and microbiological criteria per EORTC/MSG guidelines. Results: The mean age of patients was 55.5 ± 3.02 years, with a male predominance (64.66%, male-to-female ratio 1.8:1). The most frequent symptoms included dyspnea (61.3%), fever unresponsive to antibiotics (59.3%), and cough (56.6%). Radiological findings primarily showed consolidation (52%). Fungal smear positivity was observed in 52% of cases, with Aspergillus flavus being the most commonly isolated species (62.06%). The galactomannan ELISA assay had a positivity rate of 37.33%, with a statistically significant correlation to fungal culture and smear findings (p < 0.001).No cases were classified as "proven IA," while 37.33% were "probable IA," and 62.66% were "possible IA." Conclusion: The study underscores the importance of combined diagnostic approaches, including galactomannan ELISA, microscopy, and fungal culture, to ensure early and accurate detection, enabling timely management of pulmonary aspergillosis.