A 69-year-old man with clinical Stage T1cN0M0 prostate cancer underwent radical prostatectomy, revealing negative surgical margins, focal capsular penetration, and negative lymph nodes and seminal vesicles. Five years later, his prostate-specific antigen level had increased to 0.2 ng/mL, and digital rectal examination revealed a palpable submucosal mass in the rectum that was confirmed by colonoscopy and transrectal ultrasonography. Excisional biopsy revealed prostatic adenocarcinoma similar in appearance and grade to the initial needle biopsy. This case report illustrates an extremely rare needle tract adenocarcinoma implantation after needle biopsy of the prostate.