A patient with actinomyces infection of the submandibular soft tissue was diagnosed by fine needle aspiration cytology (FNAC). A 38-year-old woman presented with a right submandibular mass which slowly grew in size over one month. Clinically and radiologically, the lesion was considered as tuberculous lymphadenitis or cellulitis. The polymerase chain reaction for tuberculosis was done by aspirated specimen but the result was negative. The smears of aspiration cytology showed characteristic colonies (sulfur granules) of actinomyces in inflammatory background. After antibiotic therapy for eight months, the patient has been well, showing no detectable mass. This patient was simply and rapidly diagnosed by FNAC and can avoid unnecessary surgical biopsy.