Introduction Pulmonary involvement in microscopic polyangiitis (MPA) is common, little is known about the clinical features of MPA with interstitial pneumonia (MPA-IP). Objectives This study aimed to explore the prevalence of microscopic polyangiitis associated usual interstitial pneumonia (UIP)(MPA-UIP) and compare its clinical features and prognosis with those of MPA-non-UIP and idiopathic pulmonary fibrosis (IPF). Methods A total of 73 patients with MPA-IP were identified and divided into MPA-UIP patients and MPA-non-UIP patients. The clinical characteristics and survival of MPA-UIP patients were analysed and compared with those of MPA-non-UIP patients and 68 patients with IPF. Results The results showed that 34/73 (47%) MPA-IP patients were classified as MPA-UIP patients. Compared with MPA-non-UIP patients, MPA-UIP patients tend to have longer duration of symptoms prior to diagnosis and usually have pulmonary involvement as the initial presentation. However, they were less likely to have proteinuria and/or hematuria. Compared with IPF patients, MPA-UIP patients usually had multisystem damage, positive anti-neutrophil cytoplasmic autoantibodies and elevated levels of nonspecific inflammatory markers. MPA-UIP death was concentrated mainly in the first 3 months after diagnosis and resulted in a higher early mortality compared with IPF. Conclusion UIP is the most frequent type of MPA-IP. These patients tend to have longer duration of symptoms prior to diagnosis and usually have pulmonary involvement as the first presentation. However, they are less likely to have proteinuria and/or hematuria. MPA patients with UIP can be differentiated from IPF patients through comprehensive analysis of clinical and laboratory findings.