The treatment of post-covid pulmonary fibrotic abnormalities remain a challenge in severe COVID19 survivors.  Aims and Objectives: To evaluate the efficacy and safety profile of pirfenidone in subjects who present clinical-radiological signs of pulmonary fibrosis after severe SARS-COV2 pneumonia. Methods: Randomized multicenter double-blind phase-II placebo-controlled clinical trial that included patients with post-covid19 pulmonary fibrotic-like changes after at least one-month of hospital discharge. Patients received treatment for 6 months. The main endpoint was the rate of patients that improved (%FVC-change and high-resolution computed tomography (HRCT) fibrotic score). Results: 113 patienets were randomized. Most were male (74%), mean age 63.7 years and 50% had required tracheal intubation and mechanical ventilation during hospital stay. Mean HRCT-score was 20%(+/-14.8), mean FVC% 78(+/-19) and DLCO% 58.5(+/-19) at randomization, 49% required oxygen at home and 95% were receiving oral glucocorticoids. Although no statistically significant differences were found in the rate of patients that improved between groups, the mean percentage of FVC improvement was +12.74%(10.6) with pirfenidone and +4.35%(22) with placebo (p=0.06). Fibrotic-score reduction was -5.3% with pirfenidone and -2.5% with placebo. Clinically significant K-BILD score improvement was observed in 55% of pirfenidone patients and 39% of placebo (p=0.19). The presence of adverse events was not statistically different. Conclusions: Most patients with fibrotic-like changes after severe covid19 improve or stabilize in both arms, but the grade of improvement with pirfenidone over 24 weeks tends to be higher.