Pilomatrixoma is a benign skin appendage tumor of hair matrix cell origin. The cytological appearance of this tumor may cause problems when attempting to establish a differential diagnosis with other neoplasms. Herein we report the aspiration cytology findings of two cases of pilomatrixoma. One case was diagnosed as atypical cell clusters initially and the other was diagnosed as pilomatrixoma. On cytologic examination, both cases showed clusters of tightly arranged basaloid cells with an uniform appearance, scanty cytoplasm and round hyperchromatic nuclei. There were histiocytes and multinucleated foreign body giant cells merged with the amorphous opaque orangeophilic materials of "ghost cells". The differential diagnosis with other neoplasms is discussed.