Recent studies have shown that several loss-of-function mouse models of prostate carcinogenesis can develop a spectrum of precancerous lesions that resemble human prostatic intraepithelial neoplasia (PIN). Here, we have investigated the malignant potential of the high-grade PIN lesions that form in Nkx3.1^+/−; Pten^+/− compound mutant mice and demonstrate their neoplastic progression in a serial transplantation/tissue recombination assay. Furthermore, we find that a majority of Nkx3.1^+/−; Pten^+/− mice greater than 1 year of age develop invasive adenocarcinoma, which is frequently accompanied by metastases to lymph nodes. Finally, we observe androgen independence of high-grade PIN lesions after androgen ablation of Nkx3.1^+/−; Pten^+/− mice. We conclude that Nkx3.1^+/−; Pten^+/− mice recapitulate key features of advanced prostate cancer and represent a useful model for investigating associated molecular mechanisms and for evaluating therapeutic approaches.