Chromosomal examination and measurement of DNA content were performed in cultured sarcoid granuloma cells obtained from lymph node specimens of 11 patients with sarcoidosis. Chromosomal studies revealed that most of the cells were aneuploid; the chromosome number ranged from the near-haploid number to the near-diploid number, and the distribution of chromosome number was fairly wide. The DNA content of individual cells was measured by Feulgen microfluorospectrophotometry. The distribution of DNA content of the granuloma cells was fairly wide and did not show any recognizable peak. Flow cytofluorometry of DNA content of the cells also revealed wide frequency distribution of the DNA content in sarcoid granuloma cells. The majority of the sarcoid granuloma cells were aneuploid or hypodiploid in the short-term primary culture, suggesting that hypodiploidy may exist in granuloma cells of patients with sarcoidosis.