Idiopathic pulmonary haemosiderosis (IPH) is a diagnosis of exclusion, which is characterized by persistent or recurrent episodes of alveolar haemorrhage. Early diagnosis of IPH, especially in the case of first‐time manifestation, is challenging because previous episodes of alveolar haemorrhage are often difficult to prove. Repeated episodes of alveolar haemorrhage can result in chronic iron‐deficient anaemia and irreversible interstitial fibrosis; thus, early recognition and intervention are desirable in terms of clinical outcome. We report a case of IPH that was diagnosed early by confirming the presence of an increased number of haemosiderin‐laden macrophages with alveolar haemorrhage in repeat bronchoscopy. We wanted to highlight that decreased but sustained attenuation of ground‐glass opacities on high‐resolution computed tomography does not always correlate with successful remission in patients with IPH. Repeat bronchoscopy can be useful in the early recognition of IPH, especially in the case of sustained opacities a few months after alveolar haemorrhage. Idiopathic pulmonary haemosiderosis (IPH) is a diagnosis of exclusion, which is characterized by persistent or recurrent episodes of alveolar haemorrhage. Early diagnosis of IPH, especially in the case of first‐time manifestation, is challenging because previous episodes of alveolar haemorrhage are often difficult to prove. We report a case of IPH, which was diagnosed early by confirming the presence of an increased number of haemosiderin‐laden macrophages with alveolar haemorrhage in repeat bronchoscopy.