Objective To study the effects of peroxisome proliferators-activated receptor (PPAR) γ on the growth of human hepatocellular carcinoma cells and explore the roles of phosphatase and tensin homologue deleted on chromosome ten (PTEN) and phospho-Akt in this process. Methods SMMC-7721 cells were treated with 15-d-PGJ2 or pioglitazone, which were two kinds of PPARγ ligands, at different concentrations. The viability of SMMC-7721 cells was evaluated by MTT assay. The cell cycle was analyzed by flow cytometry. PTEN mRNA level was determined by RT-PCR. The protein expressions of PTEN and pAkt were measured by Western blot analysis. Results It was demonstrated through MTT assay that both 15-d-PGJ2 and pioglitazone had an inhibitory effect on the growth of SMMC-7721 cells in a time- and dose- dependent manner. According to flow cytometry detection, more cells were arrested in G0/G1 phase. Increased expression of PTEN mRNA was detected in 15-d-PGJ2 or pioglitazone-treated cells through RT-PCR. Increased expression of PTEN protein and decreased expression of pAkt were confirmed by Western blot analysis. Conclusion The ligands of PPARγ could inhibit SMMC-7721 cells proliferation in a time- and dose- dependent manner. The upregulation of PTEN may be involved in the underlying mechanism.