Nuclear DNA content in soft tissue sarcoma was determined by image cytometry using archival, paraffin embedded material. In a retrospective study 138 specimens of 81 patients have been analysed. The ploidy level was correlated to clinical outcome regarding tumor volume and histological grading, the most important prognostic parameters. Ploidy has a significant prognostic value and correlates well with histological grading (p = 0.01). Tumour volume was found to be an independent prognostic factor (p = greater than 0.1) [chi 2 test]. The DNA content of the primary tumour and of multiple local recurrences remained similar.