Three new collagen markers deriving from the collagenous matrix, e.g. carboxyterminal propeptide of type I procollagen (PICP), carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP), and aminoterminal propeptide of type III procollagen (PIIINP) were used for the diagnose of prostatic bone metastases. Blood samples were obtained prior to biopsy or TURP. Serum PICP, PIIINP and ICTP were measured with commercial available RIAs and PSA by IRMA. Serum PSA was increased in patients with local prostatic cancer compared with patients with hyperplasia (p < 0.05). The level of PIIINP, ICTP, and PICP did not differ between these two groups. In patients with metastatic prostatic cancer all five markers were increased compared to the level measured in patients with localized cancer (p < 0.0001). All variables showed a significant positive relationship with alkaline phosphatase. The sensitivity ranged from 0.53 to 0.62 and specificity from 0.91 to 0.95. The sensitivity for alkaline phosphatase and PSA was 0.69 and 0.66 and specificity 0.91 and 0.68, respectively.