It is the largest horseshoe bat in Europe, with a head-body length of 56 to 70 mm, a wingspan of 350 to 400 mm, a forearm measuring between 50 and 61 mm, a weight ranging from 13 to 34 g, and a tail between 30 and 43 mm. The ears are large and mobile, measuring 21 to 26 mm. The fur is clearly bicolor with a dark brown or grayish dorsum, with yellowish and reddish tones, and a light brown ventral part. Juveniles typically have a more grayish colour compared to adults.

This species is impossible to confound with other rhinolophids due to its size and the characteristic nose leaf. The connecting process and saddle of the large horseshoe bat are usually rounded and approximately the same size.