Background: The skeleton represents one of the most common sites to be affected by metastatic tumors. About 65 % of all bone metastases come from the breast cancer in females, and from the prostatic carcinoma in males. A probable diagnostic pitfall may be encountered during the process of decalcification of the bone metastases specimens. This study aimed to evaluate the diagnostic utility of NKX3.1 and HOXB13 and compare them with the traditionally used PSA for the detection of prostatic origin of bone metastases. Material and methods: We analyzed 41 tissue specimens of bone metastases originating from prostatic carcinoma. Immunohistochemical staining of NKX3.1, HOXB13 and PSA was done with evaluation of their differential expression. Results: NKX3.1, HOXB 13 and PSA were expressed in (41/41), (39/41) and (25/41) respectively of the analyzed cases. On comparing NKX3.1 and HOXB13 positive staining, there was a statistically significant difference (P = 0.000). In addition, the frequency of positive NKX3.1 expression in decalcified bone biopsies of metastatic prostatic adenocarcinoma is statistically higher than that of PSA immunostaining (P = 0.000). We found a statistically significant difference between HOXB13 and PSA positive immunostaining (P = 0.01). Conclusion: This study demonstrates that NKX3.1 and HOXB13 are more sensitive markers than PSA for the detection of prostate carcinoma metastatic to the bone following the decalcification process. We recommend use of NKX3.1 and HOXB13, rather than PSA, in the diagnosis of bone metastases originating from prostate cancer.