The association of selected cancers with service in the US military in Vietnam. II. Soft-tissue and other sarcomas. The Selected Cancers Cooperative Study Group As part of a series of investigations into the health of Vietnam veterans, we conducted a population-based, case-control study of soft-tissue and other sarcomas between 1984 and 1988. All men born between 1929 and 1953 and diagnosed in an area covered by eight cancer registries were considered eligible. Controls were selected by random-digit dialing. Analyses of 342 men with pathologically confirmed sarcoma and 1776 controls showed that Vietnam veterans had a relative risk of 1.0 for sarcoma in comparison with men who did not serve in Vietnam (95% confidence interval, 0.6 to 1.6). Restriction of the analysis to the 254 men with soft-tissue sarcoma yielded a relative risk of 0.9 (95% confidence interval, 0.5 to 1.6). Several attributes of military service in Vietnam (eg, branch, duration of service, military region, and other characteristics that may have been associated with the use of Agent Orange) were examined, and none was associated with an increased risk for the development of sarcoma. Furthermore, no morphologic type of sarcoma was overrepresented among Vietnam veterans. Results were unchanged if Vietnam veterans were compared with (1) other veterans or (2) men who never served in the military. This study, which had 97% power to detect a relative risk of 2.0 for all sarcomas, provides no evidence that the risk for the development of soft-tissue or other sarcomas is increased among veterans 15 to 25 years following service in Vietnam. 