Tripartite motif 44 (TRIM44), a member of the TRIM protein family, has been shown to play a role in tumor development and progression. However, the potential involvement of TRIM44 in prostate cancer has not been fully explored. Therefore, in the present study, we analyzed the expression of TRIM44 in prostate cancer and assessed the role of TRIM44 in the progression of prostate cancer. Our results showed that the expression of TRIM44 was significantly upregulated in human prostate cancer cell lines. In addition, knockdown of TRIM44 significantly inhibited the proliferation, migration, and invasion of prostate cancer cells in vitro, as well as attenuated the tumor growth in vivo. Mechanistic studies showed that knockdown of TRIM44 significantly reduced the levels of phosphorylated PI3K and Akt in PC-3 cells. In conclusion, this study provided evidence that knockdown of TRIM44 inhibited proliferation and invasion in prostate cancer cells, at least in part, through the inactivation of the PI3K/Akt signaling pathway. These results suggest that TRIM44 may be a potential therapeutic target for the treatment of prostate cancer.