This study was carried out to evaluate the expressions of the p53 protein, the estrogen receptor (ER) and the progesterone receptor (PR), as well as the relationship between their expressions and clinicopathologic prognostic factors with storage duration of a paraffin block, and correlation between the p53 protein, the ER and the PR expressions in 29 cases of leiomyosarcoma of soft tissue. The expressions of the p53 protein, the ER and the PR were semiquantiatively analyzed in paraffin sections by the immunohistochemical method out of 29 cases the p53 protein, ER and PR were expressed in 9 (31.0%), 2 (6.9%) and 5 (17.2%), respectively. The expression of the p53 protein was not significantly associated with sex, age, anatomic site, tumor size, tumor depth, histological differentiation or mitotic rate (p>0.05), but statistically correlated to storage duration of a paraffin block (p=0.028). There was no significant relationship between the expression of the ER and all the clinocopathological prognostic factors with storage duration of a paraffin block (p>0.05). The expression of the PR was related to the histological differentiation (p=0.02), but not related to other clinicopathological prognostic parameters and storage duration of a paraffin block (p>0.05). The expression of the p53 protein and the PR had a significant relationship (p=0.022), but the expression of the p53 protein and the ER had no significant correlation. In conclusion, these results suggest that the expression of the p53 protein and the PR may play a role in development and growth of soft tissue leiomyosarcoma. Further studies of large numbers are needed to clarify the exact relationship between tumorigenesis and the p53 and the PR expressions in leiomyosarcoma of soft tissue.