Matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) are involved in important processes of tumor invasion and metastasis. In the study presented, matrix metalloproteinase 1 (MMP1) and 3 (MMP3), the tissue inhibitor of metalloproteinase 1 (TIMP1) and the complex MMP1/TIMP1 were measured by ELISA tests specific for these proteins in blood plasma. These components have been investigated in prostate cancer patients (PCa) with metastases (n = 18; T2, 3, 4 pN1, 2M1), prostate cancer patients without metastases (n = 29; T2, 3 pNOMO), patients with benign prostate hyperplasia (BPH; n = 29) and in healthy men (n = 35). Mean values of MMP1 and of the complex MMP1/TIMP1 were not different among the four groups. The mean values of MMP3 and especially TIMP1 were significantly higher in prostate cancer patients with metastases compared with controls, BPH patients and prostate cancer patients without metastases. Ten of these 18 patients had TIMP1 levels higher than the upper reference limit. TIMP1 concentrations correlate to the tumor stage but not to the tumor grade. These results indicate, that TIMP1 could be an potential marker for metastases in prostate cancer patients.