Background: The antifibrotic drugs nintedanib and pirfenidone are used for the treatment of idiopathic pulmonary fibrosis (IPF). We analysed the association of common profibrotic polymorphisms in MUC5B (mucin 5B, rs35705950) and DSP (desmoplakin, rs2076295) on antifibrotic treatment outcomes in IPF. Methods: MUC5B rs35705950 and DSP rs2076295 were assessed in IPF patients ( n = 210, 139 men/71 women) from the Czech EMPIRE registry and age- or sex-matched healthy individuals ( n = 205, 125 men/80 women). Genetic data were collated with overall survival (OS), acute exacerbation episodes, worsening lung function and antifibrotic treatment. Results: We confirmed overexpression of the MUC5B rs35705950*T allele (55.2% versus 20.9%, p