<p>Mucormycosis is an angio-invasive fungal infection affecting individuals with immuno-compromised state. The case series is a retrospective analysis of patients in a single centre and highlights the surge of pulmonary involvement in patients with sinonasal mucormycosis. To determine incidence of sequential pulmonary involvement in diagnosed cases of sino-nasal mucormycosis undergoing treatment in a tertiary health care facility and devise institutional algorithm for management. Records of patients diagnosed with sino-nasal mucormycosis who underwent treatment in tertiary care health facility from January 2023 to January 2025 were reviewed in view of simultaneous pulmonary involvement. We found four patients during the time duration of two years with simultaneous sino-nasal and pulmonary mucormycosis. Diabetes mellitus was most common predisposing factor in all patients with mean glycosylated haemoglobin of 10.9%. Sputum microscopy for KOH mount was negative in all four patients. One of the patients underwent computed tomography guided biopsy from right lung lesion after the onset of pulmonary symptoms. Histo-morphological features were consistent with clinical diagnosis of mucormycosis. Detection of simultaneous pulmonary involvement in sino-nasal mucormycosis is an arduous task. Timely detection of non-specific symptoms of pulmonary involvement is responsible for favourable prognosis. However, diagnosing pulmonary mucormycosis can be challenging due to low threshold to perform invasive diagnostic procedures, the limited sensitivity of sputum microscopy, and presence of non-specific symptoms.</p>