Size
The Scottish Terrier is a little larger on average: about 9.5 kg (21 lb) as an adult, against 8 kg (18 lb) for the Cesky Terrier.
Shedding
Their coats shed differently: the Cesky Terrier sheds through the year, the Scottish Terrier holds loose hair until it is brushed or clipped out.
Grooming
The Cesky Terrier needs more grooming, daily brushing, where the Scottish Terrier needs a brush once a week.
Temperament
They differ most on affection (Cesky Terrier: affectionate on its own terms; Scottish Terrier: likes its own space) and on independence (Cesky Terrier: cooperative, with its own ideas; Scottish Terrier: decides for itself).