Chondromyxoid fibroma (CMF) is a rare, benign cartilaginous tumor that often occurs in the metaphyses of long bones. Tumors of the craniofacial bones are extremely rare and most often involve the mandible and the maxilla. This report presents the clinicopathological and radiological features of two unusual cases of CMF arising in the paranasal sinuses that presented with nasal obstruction. The tumors arose in the sphenoid and ethmoid sinuses and were treated by curettage and resection, respectively. One of the two patients was 20 days old, suggesting a possible congenital origin.