This study was designed to determine the frequency of structural genetic abnormalities of chromosome 17 and the incidence of TP53 mutations as they relate to the biological behavior of adult soft tissue sarcomas. We analyzed a group of 73 soft tissue sarcomas of adults that were clinically and pathologically well characterized using molecular genetic techniques and expression studies. We then correlated genotype and phenotype with pathological parameters. Overall, allelic loss of 17p and 17q was identified in 53 and 29% of informative cases, respectively. p53 nuclear overexpression was detected in 34% of the tumors analyzed. We observed an association between 17p deletions and tumor presentation being more frequent in recurrent and metastatic tumors than primary lesion. p53 nuclear overexpression was associated with tumor grade, size, and more frequently detected in metastatic than primary sarcomas. The 11 intragenic mutations characterized included 10 cases of single base substitution and one single base deletion; 8 were of the missense type and 3 were nonsense. It is concluded that 17p deletions and TP53 mutations are common events in adult soft tissue sarcomas and that due to the trends observed with the cohort of patients analyzed they may become prognostic markers for patients affected with these tumors.