Prostate cancer poses a major public health problem in men. Metastatic prostate cancer is incurable, and ultimately threatens the life of patients. Lysine‑specific demethylase 1 (LSD1) is an androgen receptor‑interacting protein that exerts a key role in regulating gene expression and is involved in numerous biological processes associated with prostate cancer. Cisplatin, also known as cis‑diamminedichloroplatinum or DDP, is a standard chemotherapeutic agent used to treat prostate cancer; however, it has the disadvantage of various serious side effects. The present study aimed to investigate the effects of LSD1 knockdown, and the interplay between LSD1 and DDP, on prostate cancer cell proliferation, apoptosis and invasion, and, therefore, the potential of LSD1 as a target for prostate cancer therapy. Flow cytometric analysis, Cell Counting kit 8 assay, Transwell assay and western blotting results revealed that LSD1 knockdown, in combination with DDP treatment, exerted antiproliferative, proapoptotic and anti‑invasive effects on PC3 prostate cancer cells. In addition, knockdown of LSD1 acted synergistically with DDP, thereby enhancing the induction of apoptosis, and the inhibition of proliferation and invasion in prostate cancer cells. These results indicated that LSD1 may serve as a potential therapeutic target, and may enhance the sensitivity of PC3 cells to DDP.