A 6-year-old, neutered, crossbreed, female dog was presented for a well-defined subcutaneous mass on the head evolving for a year. An ultrasound exam revealed a well-circumscribed, oval, heterogeneous and hyperechoic soft tissue mass, with hyperechoic internal foci, a hypoechoic peripheral rim, a cystic fluid component and a high vascularisation in colour Doppler. An isolated hair was also detected and removed from the fluid component. The mass was sampled and histological examination suggested a benign pilomatricoma. The owner declined further investigation and complete resection of the mass. This is the first report of ultrasonographic features of a pilomatricoma in a dog.