Abstract: The invention relates to methods for determining tumor aggressiveness and molecular subtype of metastases that are present, or that may eventually develop, in a subject diagnosed with prostate cancer. The methods of the invention comprise determining the molecular subtype of a sample by evaluating levels of subtype-associated gene transcripts. The invention further relates to methods for determining the metastatic potential in a subject diagnosed with prostate cancer and having a primary tumor, as well as to methods for determining the treatment for a subject diagnosed with prostate cancer metastasis.