To evaluate the efficacy of pirfenidone in patients with rapidly progressive interstitial lung disease (RPILD) related to clinically amyopathic dermatomyositis (CADM), we conducted an open-label, prospective study with matched retrospective controls. Thirty patients diagnosed with CADM-RPILD with a disease duration <6 months at Renji Hospital South Campus from June 2014 to November 2015 were prospectively enrolled and treated with pirfenidone at a target dose of 1800 mg/d in addition to conventional treatment, such as a glucocorticoid and/or other immunosuppressants. Matched patients without pirfenidone treatment (n = 27) were retrospectively selected as controls between October 2012 and September 2015. We found that the pirfenidone add-on group displayed a trend of lower mortality compared with the control group (36.7% vs 51.9%, p = 0.2226). Furthermore, the subgroup analysis indicated that the pirfenidone add-on had no impact on the survival of acute ILD patients (disease duration <3 months) (50% vs 50%, p = 0.3862); while for subacute ILD patients (disease duration 3-6 months), the pirfenidone add-on (n = 10) had a significantly higher survival rate compared with the control subgroup (n = 9) (90% vs 44.4%, p = 0.0450). Our data indicated that the pirfenidone add-on may improve the prognosis of patients with subacute ILD related to CADM.