In recent years, cases involving terbinafine-resistant Trichophyton isolates have been reported increasingly, particularly in India. We present 14 cases of terbinafine treatment failure in Trichophyton -infected Danish patients due to acquired resistance. Patients infected with Trichophyton rubrum ( n = 12) or Trichophyton interdigitale ( n = 2) with elevated terbinafine MICs during 2013–2018 were included.