Background and objectives: Pulmonary aspergillosis is a serious fungal infection and its etiological agent is the fungi of the genus Aspergillus. The infection mainly affects immunocompromised individuals and has a high mortality rate among them, related to the difficult diagnosis and treatment. Due to the difficulty to obtain positive results for Aspergillus in traditional methods of laboratory culture, it becomes necessary to evaluate alternative techniques for the detection of this microorganism. One of the advances in the diagnosis of aspergillosis is the galactomannan test, which detects this fungal cellular membrane polysaccharide that is released in the host bloodstream during infection. Methods: This study consisted of an analysis of 24 hospitalized patients in the period of 2012 to 2013, in a tertiary hospital of the Rio Grande do Sul State, Brazil. For epidemiological analysis, the following data about the patients were collected: age, sex, hospitalization unit, underlying disorders, clinical and radiological data, antimicrobial use and results of the galactomannan test. Results: 10 patients (41.6%) showed positive results in the galactomannan test. The individuals had prolonged neutropenia mainly as a result of hematologic malignancies. A persistent fever despite the use of broad-spectrum antibiotics was the main clinical sign associated with suspected invasive pulmonary aspergillosis. Conclusion: This study established the clinical profile of patients with suspected API characterized by prolonged fever and neutropenia.