Ovarian cancer (OC) is one of the most lethal gynecological malignancies in the world. The aim of the present study was to examine the role of microRNA (miR)-134-3p in OC. Reverse transcription-quantitative PCR was used to measure the expression levels of miR-134-3p. Cell Counting Kit-8, TUNEL, flow cytometric and colony formation assays were performed to examine the effects of miR-134-3p on OC cell proliferation. Moreover, wound healing and Transwell assays were performed to examine the effects on migration and invasion. In addition, western blot analyses were used to assess protein expression. Finally, the target genes of miR-134-3p were analyzed by bioinformatics analysis and dual-luciferase reporter assay. The results revealed that miR-134-3p expression was low in OC cells compared with in normal ovarian cells. The overexpression of miR-134-3p decreased cell viability, facilitated cell apoptosis, inhibited cell proliferation and arrested the cell cycle in SKOV-3 and OVCAR-3 cells. Furthermore, transfection using a miR-134-3p mimic inhibited the migration and invasion of SKOV-3 and OVCAR-3 cells, and decreased the protein expression levels of cyclooxygenase-2, matrix metalloproteinase (MMP)2 and MMP9. Bioinformatics analysis indicated that one of the potential target genes of miR-134-3p was flap structure-specific endonuclease 1 (FEN1), which was confirmed by dual-luciferase reporter assay. Moreover, overexpression of miR-134-3p decreased the expression levels of FEN1 in SKOV-3 and OVCAR-3 cells. Additionally, overexpression of FEN1 reversed the effects of the miR-134-3p mimic on the proliferation, migration and invasion of SKOV-3 and OVCAR-3 cells. Overall, the findings of the present study demonstrated that miR-134-3p may inhibit OC cell proliferation, migration and invasion by directly targeting FEN1.