The PTCLs represent a rare and aggressive subgroup of NHLs that do not respond favorably to traditional chemotherapies. Since the majority of patients with PTCL experience disease relapse or disease that is refractory to previous agents, the continued development of novel targeted therapies is critical and necessary to improve outcomes in this aggressive, difficult-to-treat, heterogeneous group of malignant disorders. The FDA approval of belinostat provides clinicians with an additional option to offer heavily pretreated patients with relapsed or refractory PTCL who did not achieve a desirable response to traditional chemotherapy agents. Belinostat may be a worthwhile treatment option for these patients because of its manageable toxicity profile and its ability to be used in patients with baseline thrombocytopenia (platelet count 50–100 × 109/L). The safety and efficacy of belinostat are currently being evaluated for use in combination with traditional front-line therapies for the treatment of PTCL. The results of these trials have the potential to expand belinostat’s place in therapy and challenge the traditional treatment approach for PTCL.