OBJECTIVE: To review the utility of tumormarkers in the treatment of germ cell testicular tumors.METHODS: The literature on this subject was reviewed.RESULTS/CONCLUSIONS: The tumor markers alphafetoprotein, beta-HCG and LDH are essential in themanagement of germ cell tumors. They are useful for theinitial diagnosis and postoperatively, particularly in thedetection of residual disease following surgery in stage Itumors. Their role as a prognostic marker has been clearlyestablished in the IGCCCG classification. Furthermore,these markers are useful for follow-up, detection of tumorrecurrence and for monitoring response to therapy.Spurious increases of marker levels unrelated withtumor progression may occur and should be recognized.The increase in alpha-fetoprotein levels can be caused byliver damage and tumor lysis, and the increase in betaHCG levels can be caused by hypogonadism, tumor lysis,or may be a discordant increase or hook effect.