Poorly differentiated synovial sarcoma is a variant of synovial sarcoma. We report a case of poorly differentiated synovial sarcoma imprinted after resection. The patient was a 47-year-old woman with a right shoulder pain for 6 months. The cytologic features showed malignant round to oval, monotonous tumor cells with high nuclear to cytoplasmic ratio. Some tumor cells showed perivascular distribution and nuclear melding. Vague rosette-like structures were seen. On immunohistchemical stains, tumor cells were diffusely positive for CD99 and focally positive for epithelial membrane antigen. Ultrastructural examination showed desmosomes and microvilli.