Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive variant of squamous cell carcinoma (SCC) that occurs preferentially in the upper aerodigestive tract. Since the first description by Wain SL et al., in 1986, only 21 cases with BSCC in the nasal cavity or in the paranasal cavity have been reported in the English literature. We present here a case of BSCC arising in a paranasal sinus. The case was a 51-year-old male patient with four months history of right cheek swelling and unilateral nasal obstruction, who received operation and postoperative radiotherapy. Clinical, surgical and pathological findings in this case, including immunohistochemistry is presented along with brief discussion of literature.